EFFECT FO DIETARY PROTEIN ENERGY LEVELS ON
Transcription
EFFECT FO DIETARY PROTEIN ENERGY LEVELS ON
EFFECT FO DIETARY PROTEIN ENERGY LEVELS ON PERFORMANCE OF DEBILITATED NUBIAN GOATS By AISHA BABIKER MOHAMMED AHMED B.V.Sc. (1982), University of Khartoum, M.V.Sc. (1992), University of Khartoum. A Thesis submitted in accordance with the requirements of the University of Khartoum for the Degree of Doctor of Philosophy. Supervisor: Prof. Amir Mohammed Salih Mukhtar Department of Animal Nutrition, Faculty of Animal Production, University of Khartoum. Co-Supervisor: Dr. Ahmed El Amin Mohammed Department of Medicine, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Khartoum. Department of Animal Nutrition, Faculty of Animal Production, University of Khartoum, Dec' 2008. Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Dedication To soul of my parents, Who raised me up with compassion To my teachers, Who gave me faith To challenge the unknown And To my family and extended family Aisha Dec' 2008 ii Ahmed, Aisha B. M. , Ph.D Thesis, 2008 ال عِلْ َم لَنَا إِالَ مَا عَلَمْتَنَا {قَالُو ْا سُبْحَانَكَ َ إِنَكَ أَنتَ الْعَلِيمُ الْحَكِيمُ } صذق اهلل العظيم سورة البقرةاآليت 43 ّن لَكُمْ فِي اَّنْعَا ِم لَعِبْ َرةً نُسْقِيكُمْ مِمَا فِي بُطُونِهَا {وَِإ َ وَلَكُ ْم فيِهَا مَنَافِ ُع كَثِي َر ٌة وَمِنْهَا تَأْكُلُوّنَ} صذق اهلل العظيم سورة المؤمنون االيه()32 iii Ahmed, Aisha B. M. , Ph.D Thesis, 2008 CONTENTS Page viii ix x xi xii xiii xiv Item List of Tables List of Figures List of Plates List of Abbreviations Acknowledgements Abstract Arabic abstract INTRODUCTION 1 5 CHAPTER ONE LITERATURE REVIEW 1.1 1.2 1. 2.1 1.2.2 1.2.3 1.2.4 1.2.5 1.2.6 1.3 1.3.1 1.3.1.1 1.3.1.2 1.3.1.3 1.3.1.4 1.3.1.4.1 1.3.1.4.2 1.3.1.4.3 1.3.1.4.4 1.3.1.4.5 1.3.1.4.6 1.3.1.4.7 1.3.1.5 5 5 6 7 8 8 9 9 9 10 10 12 15 17 18 18 19 20 21 21 21 22 Goat classification Sudan goat breeds Nubian goats Desert goats Nilotic goats Mountain goat (Taggar) Baggara goat Crossbred goats Goat nutrition Nutrient requirements of goats Energy Protein Energy /protein requirement Minerals requirement Calcium Sodium Potassium Phosphorus Magnesium NaCl salt Zinc Vitamins requirement iv Ahmed, Aisha B. M. , Ph.D Thesis, 2008 1.3.1.6 1.4 1.5 1.6 1.6.1 1.6.2 1.6.3 1.6.4 1.6.4.1 1.6.4.2 1.7 1.7.1 1.7.1.1. 1.7.1.2 1.7.2 1.7.2.1 1.7.2.2 1.7.2.3 1.7.3 1.8 1.9 Water requirement Feed intake Body weight Goat health Clinical examination Physical examination Environmental examination Laboratory examination Blood and plasma parameters Clinical Chemistry Wasting diseases Nutrition-related Causes Primary nutritional problems Secondary nutritional problems Chronic affections Viral causes Bacterial causes Parasitic causes Miscellaneous causes Under nutrition Compensatory growth 22 23 25 26 26 26 29 30 30 32 35 35 35 36 37 37 38 38 39 40 44 CHAPTER TWO 47 MATERIALS AND METHODS 2.1 2.1.1 2.1.2 2.1.2.1 2.1.2.2 2.1.2.3 2.1.2.4 2.1.2.5 2.1.2.6 2.2 2.2.1 2.2.2 2.2.3 2.2.3.1 Nutritional and health profile of debilitated Nubian goats Experimental animals Data collected Liveweigh Management Clinical examination Blood Serum Internal parasites Protein realimentation of adult debilitated Nubian goats Experimental animals and housing Experimental rations Data collected Performance v 47 47 47 47 47 47 47 48 48 48 48 49 50 50 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.2.3.2 2.2.3.3 2.3 2.3.1 2.3.2 2. 3.3 2.3.3.1 2.3.3.2 2.3.3.3 2.4 2.4.1 2.4.1.1 2.4.1.2 2.4.1.3 2.4.1.4 2.4.1.5 2.4.1.6 2.4.1.7 2.4.1.7.1 2.4.1.7.2 2.4.1.7.3 2.4.2 2.4.2.1 2.4.2.1.1 2.4.2.1.1.1 2.4.2.1.1.2 2.4.2.1.1.3 2.4.2.1.2 2.4.2.1.2.1 2.4.2.1.2.2 2.4.2.1.2.3 2.4.2.1.2.4 2.4.2.1.2.5 2.4.2.1.2.6 2.4.2.1.3 2.4.2.1.3.1 Blood Serum profiles Energy realimentation of adult debilitated Nubian goats Experimental animals and housing Experimental rations Data collected Performance Blood Serum Methods Haematological methods Blood sampling Red blood cell count (RBC) White blood cell count (WBC) Differential leukocyte count Packed cell volume (PCV) Haemoglobin concentration (Hb) Red cell indices Mean corpuscular volume (MCV) Mean corpuscular haemoglobin (MCH) Mean corpuscular haemoglobin concentration (MCHC) Chemical methods Determination of serum constituents Serum enzyme activities Glutamate oxalacetate transaminase (Aspartate amino transferase, aspartate: 2-oxoglutarate aminotransferase, E.C. 2.6.1.1, GOT; AST) LDH ( Lactate dehydrogenase ) CK (Creatine kinase ) Serum metabolites Blood sugar level Total protein Albumin Urea Creatinine Total bilirubin Determination of serum electrolytes Sodium vi L- 50 50 51 51 51 51 51 52 52 53 53 53 53 53 54 54 54 54 54 55 55 55 55 55 55 56 57 58 58 58 59 60 60 61 62 62 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.4.2.1.3.2 2.4.2.1.3.3 2.4.2.1.3.4 2.5 2.6 Calcium Potassium Phosphorus Proximate analysis of experimental diets Statistical analyses CHPTER THREE 65 RESULTS 3.1 3.2 3.2.1 3.2.2 3.2.3 3.2.4 3.3 3.3.1 3.3.2 3.3.3 3.3.4 62 63 63 64 64 Nutritional and health profile of debilitated Nubian goats Protein realimentation of adult debilitated Nubian goats Performance Blood values White and differential white cell values Serum values Energy realimentation of adult debilitated Nubian goats Performance Blood values White and differential white cell values Serum values CHAPTER FOUR 65 71 71 73 73 74 75 75 77 77 77 79 DISCUSSION Concusion Practical implications Suggestions for future work 88 88 89 90 111 REFERNCES APPENDIX vii Ahmed, Aisha B. M. , Ph.D Thesis, 2008 List of Tables Table No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Title Page Percent composition (as-fed basis) and calculated chemical composition (dry- 49 matter basis) of experimental rations fed to goats at constant energy (9MJ ME / kg) and variable crude protein (12, 14, and 16%) for 11 weeks. Percent composition (as-fed basis) and calculated chemical composition (drymatter basis) of experimental rations fed to goats at constant protein (12%) and variable energy (8, 10 and 12 MJ ME / kg) for 11 weeks. Goat herds survey at Fitaih El Agaleein, 25km south of Khartoum. Goat nutrition survey at Fitaih El Agaleein, 25km south of Khartoum. Goat reproduction survey at Fitaih El Agaleein, 25km south of Khartoum. Goat health survey at Fitaih El Agaleein, 25km south of Khartoum. Goat herds haematological values at Fitaih El Agaleein, 25km south of Khartoum. Goat herds serum metabolites, enzymes and minerals values at Fitaih El Agaleein, 25km south of Khartoum. Performance values of experimental adult goats fed at constant energy (9MJ ME / kg) and variabe crude protein for 11 weeks. Average (mean ± s.d.) values of red blood cells of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks. Average (mean ± s.d.) values of white and differential white blood cells of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks . Average (mean ± s.d.) values of serum parameters of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks. Performance values of experimental adult goats fed at constant protein (12%) and variable energy for 11 weeks. Average (mean ± s.d.) values of red blood cells of experimental adult goats fed at constant (12%) crude protein and variable energy for 11 weeks. 52 65 66 67 68 70 70 71 73 74 75 75 77 78 Average (mean ± s.d.) values of white and differential white blood cells of experimental adult goats fed at constant 12% protein and variable energy for 11 weeks . Average (mean ± s.d.) serum parameters of experimental adult goats fed at 78 constant (12%) protein and variable energy for 11 weeks. viii Ahmed, Aisha B. M. , Ph.D Thesis, 2008 List of Figures Figure No. 1 2 3 4 5 6 7 8 Title Page Growth curve of the control group A fed at 6MJ ME / kg and crude protein 8% for 11 weeks. Growth curve of experimental group B fed at constant energy (9MJ ME / kg) and crude protein 12% for 11 weeks. Growth curve of experimental group C fed at constant energy (9MJ ME / kg) and crude protein 14% for 11 weeks. Growth curve of experimental group D fed at constant energy (9MJ ME / kg) and crude protein 16% for 11 weeks. Growth curve of the control group A fed at 6MJ ME / kg and crude protein 8% for 11 weeks. Growth curve of experimental group B fed at constant crude protein 12% and energy 8 MJ ME / kg for 11 weeks. Growth curve of experimental group C fed at constant crude protein 12% and energy 10 MJ ME / kg for 11 weeks. Growth curve of experimental group D fed at constant crude protein 12% and energy 12 MJ ME / kg for 11 weeks. ix 72 72 72 72 76 76 76 76 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 List of Plates Plate No. Title Page 1 Housing facilities of experimental goats 2 Feeding trough of experimental goats 48 48 x Ahmed, Aisha B. M. , Ph.D Thesis, 2008 LIST OF ABBREVIATIONS Abbrev. Denotation Abbrev. Denotation ADG Average daily gain MCHC BUN Blood urea nitrogen MCV Mean Corpuscular volume BW Body weight MDH Maltate dehydrogenase CF Crude fiber ME Metabolizable energy CK Creatine kinase MEa Metabolizable energy required for activity CP Crude protein MEg Metabolizable energy required for gain Creatine phosokinase MEm Metabolizable energy CPK Mean Corpuscular hemoglobin concentration for maintenance DCP Digestible crude protein MJ Mega Joule DM Dry matter. MPg Metabolizable protein required for gain Ether extract. MPm Metabolizable protein for maintenance FCR Feed conversion ratio MXD Summation of basophils, eosinophils and monophils HCT Hematocrit value NEUT Neutrophils HGB Hemoglobin NFE Nitrogen-free extract Kg Kilogram RBC Red blood cell KJ Kilo Joule SE Starch equivalent LDH Lactate dehydrogenase TP Total protein LYM Lymphocytes UN Undegraded protein MCal Mega Calorie W 0.75 Metabolic weight MCH Mean Corpuscular hemoglobin WBC White blood cell EE xi Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Acknowledgements First, praise be to Allãh, the Lord of the Worlds, who permitted health and help to complete this work. My Lord is the hearer of prayer. I wish to express my thanks and deep gratitude to my supervisor Prof. Amir Mohammed Salih Mukhtar, Department of Animal Nutrition, Faculty of Animal Production, University of Khartoum, for his precious guidance, patience and encouragement throughout this work. I wish also to express my thanks and deep gratitude to my Co-Supervisor Dr. Ahmed El Amin Mohammed, Department of Medicine, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Khartoum, for his useful guidance, encouragement and patience. My thanks are also offered to Dr. Mohammed El Fatih Awad, Head Department, Animal Production, Faculty of Agriculture, Omdurman Islamic University, and to Dean Faculty and Staff. Thanks are extended to the Head and Staff of the Department of Animal Nutrition, Faculty of Animal Production, University of Khartoum, and to Hanan Nimtalla Jibril and Afraa Tag Elsir ElAtta, Department of Medicine, Pharmacology and Toxicology, University of Khartoum. Thanks are also directed to the Librarians at Shambat Library, Shambat Digital library, University of Khartoum and the Arab Organization For Agricultural Development Library. Thanks are due to Abu Zar Mouhamed A/Elgader, Khartoum Hospital, for facilitation of laboratory analyses. The help offered by Fitaih El Agaleein people during the survey is acknowledged, and to Hag Mudawwi Farm at El Dikhianat. Thanks are offered to Mrs Samia Gasmasseed and Omimah abbas for rapid and efficient typing of the Thesis. My thanks are extended to all of my family members and relatives for their continuous materialistic and moral help and support and to all of those who offered help, not being mentioned here, to the completion of this study. Aisha Dec.’ 2008 xii Ahmed, Aisha B. M. , Ph.D Thesis, 2008 EFFECT FO DIETARY PROTEIN ENERGY LEVELS ON PERFORMANCE OF DEBILITATED NUBIAN GOATS By AISHA BABIKER MOHAMMED AHMED ABSTRACT This study was conducted to investigate the performance and health of debilitated stray goats and effects on subsequent re-alimentation at different energy/protein ratios. Eighty adult apparently healthy female Nubian goats of a debilitated condition were surveyed in the field for the nutritional and health profiles. Data were collected on liveweight, management, clinical examination, blood complete haemogram, serum metabolic indicators, electrolytes and enzyme activities. Two experiments, each of twelve adult apparently normal female Nubian goats of a debilitated condition as selected for Experiment 1 were used. They were dvided into 4 groups to investigate the performance and health values on protein realimentation at 8%, 12%, 14% and 16%crude protein( CP) at constant energy 9 MJ ME/kg; and energy re-alimentation at 6, 8, 10 and 12 MJ ME/kg at constant 12% CP. In both experiments data were collected on performance, blood complete haemogram, serum metabolic indicators, electrolytes and enzyme activities. Half of the herds in the area were medium in size (10-20 heads). The Nubian goats were 93% of them and only 7% were local crosses. About 83% of the surveyed goats had body weight range of 20 – 30 kg. Herds were 86% managed in the range. The majority (86%) of goats feed on pasture with supplements offered at the end of grazing. Insemination occurs soley naturally. Most goats (45%) conceive once per annum. Lactating goats spent 2-6 month on lactation. Ninety percent of the herd looked normal in appearance. Foreign body appeared in 9% of the goats. Internal parasites infestation detected was mild to moderate coccidia , mild strongyloides and moderate monieziasis. Mixed infestations were seen. Values for white cells were within the normal range. RBCs count was very low; MCV and MCH values were very high. Values, Hb, PCV and MCHC were within the normal limits. Serum metabolites, enzymes and minerals tested fell within the normal ranges except for LDH which was found high. For protein realimentation at constant energy, feed intake and daily body weight directly varied with the crude protein content in the diet and and both were higher in group D (16% CP). The highest crude protein-fed Group D had the best xiii Ahmed, Aisha B. M. , Ph.D Thesis, 2008 feed conversion ratio. All of the growth rates were inferior to the control group with Group C growing at a superior rate to the other experimental groups. All of the red cells and their indices, white and differential white cells of the test groups, were not affected by the increase in CP in the diet, except number and percentage of neutrophils which were decreased (p>0.05) in all test groups. Most metabolites and calcium were not affected by the increase of crude protein in the diet. Creatinine increased (p>0.05) in all test groups, while phosphorus increased significantly (p<0.05)with crude protein increase in all test groups. The AST activity decreased (p>0.05) with the increase of crude protein in the diet. For energy realimentation at constant protein, feed intake was lowest in group D and highest in group B. Body weight gain was lowest in group D goats fed the highest energy level. The goats fed lowest energies (groups B and C) had food conversion ratios11.10 and 10.50 respectively, while group D (highest energy) had the best feed conversion ratio (10.10). Growth rates of groups B and D were inferior to the control group (0.72). Group C coefficient (0.87) is superior to the control group. The RBCs and their indices were not affected by the increase of ME in the diet. WBC and lymphocytes were also not affected by the increase of ME in the diet. Lymphocytes increased (p>0.05) in number and percentage in all test groups while neutrophils decreaed in number and percentage (p<0.05) in test groups Cand D. Grouped basophils, eosinophils and monocytes decreased (p>0.05) in number and percentage in all test groups. Glucose, albumin, creatinine, calcium and AST values were not affected (p>0.05) by the increase of ME in the diet. Group D only showed a significant (p<0.05) decrease in total protein and globulin. Phosphorus increased significantly (p<0.05) in all test groups. Adult debilitated goats though look unthrifty, yet healthy enough to survive shortages in feed and discrepant management. Due to their age (adulthood) and the low plane of nutrition received during their growth phase, no compensatory growth can be expected. xiv Ahmed, Aisha B. M. , Ph.D Thesis, 2008 إعذاد عائشت بابكر محمذ أحمذ المستخـلص أجزَذ هذِ انذراسخ نجحث أداء وصحخ انًبػش انُىثٍ انسبئت ،انجبنغ وانهشَم ػُذ إػبدح رغذَزخ ثبنغبقخ :انجزورٍُ ثًخزهف انُست. رى يسح حقهٍ نثًبٍَُ يؼشٌ َىثُخً هشَهخ و ثصحخ ظبهزَخ جُذح نًؼزفخ رغذَزهب وصحزهب .جًؼذ ثُبَبد يٍ انىسٌ انحٍ و انزػبَخ و انحبنخ اإلكهُُُكُخ و قُبسبد انذو و يؤشزاد انًصم األَضُخ و انكهبرل وَشبط اإلَشًَبد. أجزَذ رجزثزبٌ اسزخذاو فٍ كم يُهًب اثٍُ ػشز يؼشًٌ َىثُخً هشَهخ كًب اإلخزُبر فٍ انًسح انحقهٍ، قسًذ إنٍ أرثغ يجًىػبد نزقُُى األداء وانحبنخ انصحُخ ػُذ إػبدح انزغذَخ يزح ثًسزىَبد % 8و %12و %14و %16ثزورٍُ خبو يغ ثجىد انغبقخ ػُذ 9يُجبجىل عبقخ يًثهخ/كُهى؛ ويزح ثًسزىَبد 10 ،8 ،6و 12يُجبجىل عبقخ يًثهخ /كُهى ػُذ ثجىد انجزورٍُ انخبو ػُذ .%12جًؼذ يؼهىيبد فٍ انزجزثزٍُ ػٍ األداء و قُبسبد انذو و يؤشزاد انًصم األَضُخ و انكهبرل وَشبط اإلَشًَبد. كبَذ َصف انقغؼبٌ فٍ انًُغقخ يزىسغخ انحجى ( 20- 10راص) و %93يُهب يبػش َىثً و%7 يحهُخ يهجُخ .حىانٍ % 83يٍ انًبػش انزٍ اجزٌ ػهُهب انًسح انحقهٍ رقغ اوساَهب فٍ انًذي 30-20كجى, و % 86يٍ انقغؼبٌ رزػً فٍ انًزاػٍ انًفزىحخ .يؼظى انًبػش ( )%86رزغذي ثبنزػٍ يغ رُبول إضبفبد ثؼذ انؼىدح يٍ انًزػً .انزهقُح َزى عجُؼُبً فقظ .يؼظى انًبػش ( )%45رحًم يزح واحذح فٍ انؼبو .فززح انحهُت 6-2شهىر .رجذو % 90يٍ انقغؼبٌ عجُؼُخ فٍ يظهزهب .وجذد االجسبو انغزَجخ فٍ %9يٍ انًبػش .اإلصبثبد انغفُهُخ انذاخهُخ انًزصىدح كبَذ كىكسُذَب خفُفخ انً يزىسغخ ,دَذاٌ اسززوَقهىَذس خفُفخ ودودح يىَُشَب انشزَغُخ ثئصبثخ يزىسغخ ,كًب ظهزد إصبثبد يخزهغخ .كبَذ قُبسبد خالَب انذو انجُضبء فٍ انحذود انغجُؼُخ وػذد كزَبد انذو انحًزاء قهُم جذًا .كبٌ يزىسظ حجى انخهُخ انحًزاء ويزىسظ هًقهىثُُهب ػبل جذاً ,ثًُُب كبَذ قُى انهًقهىثٍُ ،حجى انخالَب انًززاص ويزىسظ رزكُش انهًقهىثٍُ انخهىٌ فٍ انحذود انغجُؼُخ كبَذ انقُبسبد األَضُخ ،اإلَشًَُخ وانكهبرل فٍ انًصم فٍ انحذود انغجُؼُخ ػذا َشبط إَشَى َبسع هبَذروجٍُ انالكزُذ وانذٌ وجذ ػب نُبً. ػُذ إػبدح انزغذَخ ثبنجزورٍُ يغ ثجىد انغبقخ ،رغُز انًأكىل انغىػٍ وانىسٌ انُىيٍ رغُزاً عزدَبً يغ يحزىٌ انجزورٍُ انخبو فٍ انغذاء ،وكبَب األػهٍ فٍ انًجًىػخ د ( %16ثزورٍُ خبو) .انًجًىػخ انزٍ أعؼًذ أػهً يسزىي ثزورٍُ خبو وهٍ انًجًىػخ د أػغذ أحسٍ كفبءح رحىَهُخ نهغذاء .كبَذ يؼذالد انًُى فٍ جًُغ يجًىػبد اإلخزجبر أدًَ يٍ انًجًىػخ انًزجؼُخ وكبَذ انًجًىػخ ج رًُى ثًؼذل أػهً يٍ يجًىػبد انزجزثخ األخزٌ .نى رزأثزجًُغ خالَب انذو انحًزاء يؤشزارهب وانخالَب انجُضبء وػذادهب انزفزَقٍ نًجًىػبد اإلخزجبر ثشَبدح انجزورٍُ انخبو فٍ انؼهُقخ يبػذا انخالَب انًزؼبدنخ وانزٍ قهذ (ة > )0.05فٍ انؼذد وانُسجخ انًئىَخ فٍ كم يجًىػبد اإلخزجبر .يؼظى انًئُضبد وانكبنسُىو نى رزأثز ثشَبدح انجزورٍُ انخبو فٍ انؼهُقخ .ساد انكزَبرٍُُ (ة > )0.05فٍ كم يجًىػبد اإلخزجبر ,ثًُُب ساد انفسفىر يؼُىَبً (ة < )0.05 xv Ahmed, Aisha B. M. , Ph.D Thesis, 2008 ثشَبدح انجزورٍُ انخبو فٍ انؼهُقخ فٍ كم يجًىػبد اإلخزجبرَ .شبط اَشَى َبقم أيُُى االسجبررُذ قم (ة > )0.05يغ سَبدح انجزورٍُ انخبو فٍ انؼهُقخ. ػُذ إػبدح انزغذَخ ثبنغبقخ يغ ثجىد انجزورٍُ ،كبٌ أقم يأكىل عىػٍ فٍ انًجًىػخ د وأػالِ فٍ انًجًىػخ ة .كبٌ أقم كست وسٌ حٍ فٍ انًجًىػخ د انزٍ أعؼًذ انًسزىي االػهً يٍ انغبقخ .انًجًىػبد انزٍ أػهفذ يسزىَبد انغبقخ االقم (يجًىػزٍ ة و ج ) كبَذ كفبءرهًب انزحىَهُخ نهغذاء 11.10و 10.50ػهً انزىانٍ ،فٍ حٍُ أٌ انًجًىػخ د (أػهً يسزىي عبقخ ) كبَذ أفضم انًجًىػبد كفبءح رحىَهُخ نهغذاء ( .)10.10كبٌ يؼبيم انًُى نهًجًىػزٍُ ة و د أدًَ يٍ انًجًىػخ انًزجؼُخ ( .)0.72يؼبيم انًجًىػخ ج ( )0.87أػهً يٍ انًجًىػخ انًزجؼُخ .كزَبد انذو انحًزاء ويؤشزارهب نى رزأثز ثشَبدح انغبقخ انًًثهخ فٍ انؼهُقخ .خالَب انذو انجُضبء وانخالَب انهًفُخ نى رزأثزا أَضبً ثشَبدح انغبقخ انًًثهخ فٍ انؼهُقخ .انؼذد وانُسجخ انًئىَخ نهخالَب انهًفُخ سادد (ة > )0.05فٍ جًُغ يجًىػبد اإلخزجبر ،ثًُُب قهذ (ة < )0.05ثبنًثم انخالَب انًزؼبدنخ فٍ انؼذد وانُسجخ انًئىَخ فٍ انًجًىػزٍُ ج و د .يجًىع انخالَب انقبػذَخ وانحبيضُخ ووحُذح انُىاح قم ػذدهب (ة > )0.05فٍ كم يجًىػبد اإلخزجبر .نى رزأثز(ة > )0.05قُى انجهكىس، االنجىيٍُ ،انكزَبرٍُُ ،انكبنسُىو وَشبط اَشَى َبقم أيُُى االسجبررُذ ثشَبدح انغبقخانًًثهخ فٍ انؼهُقخ. انًجًىػخ د هٍ انىحُذح انزٍ أظهزد َقصبً فٍ انجزورٍُ انكهٍ وانقهىثُىنٍُ .ساد انفسفىر يؼُىَبً فٍ جًُغ يجًىػبد اإلخزجبر. ثبنزغى يٍ أٌ انًؼشٌ انُىثُخ انجبنغخ انهشَهخ ركىٌ فبقذح نهىسٌ ،نكٍ ثبنزغى يٍ شح انغذاء وقصىر انزػبَخ فئَهب رسزغُغ انجقبء ثصحخ جُذح .ثبنُسجخ نؼًز انًؼشٌ (ثبنغخ) وانًسزىٌ انغذائٍ انًزذٍَ فٍ يزحهخ ًَىهب ،فال ًَكٍ رىقغ أٌ ًَى رؼىَضٍ. xvi Ahmed, Aisha B. M. , Ph.D Thesis, 2008 INTRODUCTION The Sudan is a vast country of great animal wealth and diversified climatic conditions. It is considered amongst those countries having a great agricultural potential. Small ruminants raising is important and usually may be the only animal source for people inhabiting forest regions or regions that are not suitable for crop or cattle production (Daskiran et al., 2006) Livestock in Sudan is herded by nomads, semi-nomads and transhumans of different tribes, and depend entirely on range grasses, browse trees and shrubs. Goat farming is practiced worldwide, with goat products having a favorable image , and the number of goats has increased globally, even in countries with high and intermediate incomes (Morand – Fehr et al ., 2004) despite major change in agriculture due to industrial mergers, globalization and technological advances in developed countries ( Boehlje and Sonka,1998; Cheeke, 2004). New, large-scale mohair industries, and to a lesseor extent cashmere industries, have been established in Australia and New Zealand (Yerex, 1986) and are also growing in the United States and Europe. Intensive goat dairying for cheese production is now a small but rapidly growing industry in the United States. In Asia, Africa, and Latin America there is an increasing demand for importation of established milking breeds to improve the milking potential of local meat-type goats. There is also significant interest in intensification of meat goat industries in these regions to enhance production. Goats are of economical and social importance, especially in developing and poor countries and are therefore called the poor man’s cow (Elhag, 1976). The economic importance of goats in the provision of animal proteins in developing countries has been extensively reviewed (Devendra, 1987). As an important meat animal in Africa, Asia and the Far East, the goat is now emerging as an alternative and attractive source of meat in other parts of the world (Devendra, 1990). Goat meat production system 1 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 around the world is extremely diverse and received little scientific attention compared with sheep and cattle. This may be due to the traditionally low economic significance of goats in the developing countries. Meat from small ruminants accounts for almost 30% of the meat consumed in Africa (Reed et al., 1988) and for 50% of red meat consumed in Tunisia (Ben Dhia, 1995). In the summer season of North African regions, consumption of goat meat increases traditionally because of the latter low fat content compared to that of lamb, which meat is the first choice in the rest of the year. That is, goats play a major role in the provision of animal proteins in this region. Although goats have been the common source of meat in many tropical and developing countries (Shelton,1990), goats are also an important milk supplier, particularly for people in the technologically developing regions, situated mainly in the tropics (Casey, 1992). These regions account for more than 90% of the estimated world goat population of 504 millions, with approximately 56% in Asia, 33% in Africa and 7% in South and Central America and the Caribbean (FAO, 1988) At present the total population of goats in the world is about 850.1 million (MWNZ, 2009) with approximately 54% being found in the tropics, the largest concentrations are in Africa and India subcontinent. The population of goats in Africa is approximately 218.6 million (FAO, 2003) which represent 32% of the world total. The Eastern Africa region contains the highest concentration of goats. It is estimated that the arid zone of the world contains about 39% of the goat population, in spite of low grazing potential, while the semi-arid zone has the greatest concentration of goats. The goat population in the Sudan is estimated to be 42756 thousand (AOAD, 2007), forming about 31.7% of ruminants in the country, 18.2% of goats in Africa and 5.3% of the world goat population (FAO, 1999). The goat populations in the Arab countries count 112961.16 thousand (AOAD, 2007). Approximately 6% of the world's goats are found in developed countries and 94% in developing countries (FAO, 1988). 2 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 In the Sudan, goats and sheep, as to many people of the world, play an important integral component in most traditional production systems. They provide milk for children, meat, skin, fiber and cash income from sales (Ageeb, 1992). They play a special role in achieving food and economic securities in developing regions. Little was done to raise the awareness for the potential of small ruminants, especially goats, to stimulate their introduction into animal research and economic development programmes. Goats represent the most important species of livestock in the traditional production systems due to their superior adaptation to the environment (Devendra and Mcleroy, 1987). Their inquisitive feeding habits enable them to extend their feed preferences and also perform well in situations where other ruminants may not be able to survive. Goats prefer variations in their feed and they are selective feeders (Devendra and Coop, 1982). They depend mainly on natural range in the Sudan. Feed selection in goats is affected by season, availability, stocking rate, previous experience and the physiological status. Williamson and Payne (1978) mentioned that rationing of goats should be realistic and should be based on cheap feed such as browse, pasture and agro -industrial by-products. Goats generally have higher feed intake than sheep (Wahed and Owen, 1986) and furthermore, they have better digestive efficiency than sheep for low quality forages. All breeds respond to better nutrition. Traditionally, feedlot for beef, mutton and goat meat production depend on concentrates, mainly cereals, oil cakes and some agro industrial by -products. However, consideration of the energy and protein concentrations of the diet is important. Also consideration of the economical aspect of the feed and its source is of vital importance. The nutrient requirements of goats were studied by the NRC (1981). 3 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Urban or rural goats receive meager care and almost run astray without proper management by their owners, hence become debilitated and their production decreases. The objective of this study is to evaluate the response of different debilitated Nubian goats to varying energy / protein realimentation. 4 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 CHAPTER ONE LITERATURE REVIEW 1.1 Goat classification Goats are the earliest domesticated ruminants in the world that dates back to 6000 and 7000 BC (Devendra and Mcleory, 1982 and Lillywhite, 2000). Goat belong to the Caprini Tribe of the Bovidae Family, a suborder of ruminants (Lillywhite, 2000 and Wilson, 1991).The goat Tribe is composed of five Genera, of which two are true goats. The criteria by which domestic goats can be classified are origin, body size and length, ear shape, height at withers and production purpose (Devendra and Mcleory, 1990). In Somalia and in the Sudan, Mason and Maule (1960) reported attempts to classify goat types into two large long–eared and small short- eared, like those in Central East Africa where all goats have short erect ears. According to body size and height at withers, Devendra and Burns (1983) classified goats into three categories: a- Large breeds: Height at withers is more than 65 cm and live body weight is 2063 kg. They are dual – purpose goats. b- Small breeds: Height at withers is 51-65 cm and live body weight is 19- 37 kg. They are milk-type goats. c- Dwarf breeds: Height at withers is less than 50 cm and live body weight is 18 25 kg. They are meat-type goats. 1.2 Sudan goat breeds Goat breeds in the Sudan are generally classified into local ecotypes or breeds. Four local types of goats exist in the Sudan, Nubian goat, Sudan Desert goat, Southern Sudan (Nilotic) goats and Hill (Tagger) goat (Mason and Maule, 1960 and Muffarah, 1995). Recently many other foreign breeds were introduced to the country and so there are many cross-breeds. This large population was widely distributed in all ecological 5 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 zones from arid Northern regions to humid Southern Sudan. All of these goats are classified as meat types whereas Nubian goat is dual. 1.2.1 Nubian goats The Nubian goats are found in the northern riverain Sudan (North to Khartoum), and urban areas of the lowlands of western Eritrea (Gash, Setit and Akordat) and parts of north- western Ethiopia. Its name is derived from the Nubian tribes (Kiwuwa, 1992). The climate in these areas is extremely arid except for along the rivers. Pastoral or periurban is the production system. Also Nubian goats are kept by settled agriculturalists on irrigation schemes along the Nile (Wilson, 1991 and ILRI, 1996). This goat is well known in the country. It is widely distributed north of latitude 12◦ N (Mason, 1951). The Sudanese Nubian goat belongs to the general Nubian group with heavy bodies (40-70kg), rudimentary mane , beard and wattles exist in the male. Height is 70-75cm and characterized by fairly proportioned body size with small to medium size head, the neck is of moderate length, the chest is deep and the withers are prominent. The back is long and straight, nose is Roman, large drooping ears usually turned out at the lower tips. The color is commonly black (Mason, 1951) but pure brown, pure white and different shadows between them are found. Also multicolouration of black and white are found (ELNaim, 1979 and AOAD, 1990). Horns are black and scimitar shaped and sweeping backwards (Mackenzie, 1957 and French, 1942). The legs are long, stronger and well proportioned. The udder is large and well shaped and developed (Mason, 1951; ELNaim, 1979; AOAD, 1990 and Kiwuwa, 1992; Wilson, 1991 and ILRI, 1996). The Nubian goat is dual–purpose (Luginbuhl, 1998). As a dairy goat, yield is about 1.0 – 1.25 kg/ day (Mason and Maule, 1960) or 0.5 kg / day (El Naim, 1979). Recorded milk yield in the Sudan is 72 kg in 121 days, and because of their large size; 6 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 surplus kids are suitable for meat production (Mason and Maule, 1960, Devendra and Burns, 1970 and Gall, 1996). Regarding reproductive performance, Nubian goats can give birth 3 times every two years, with 50% of twinning or triple kids (Abo – El – Azaim, 1996). Puberty can be reached by female Nubian kids within 6 months of age, and the gestation period cover146 days Muffarah (1995). Age at first kidding is 12 months and kidding interval is 228 days, birth weight is 2.3 – 2.6 kg for males and 2.1 – 2.4 kg for females (Gall, 1996). The dressing percentage is 48.1 and 55.8 on live and empty body weights respectively (Yassin, 1994). Meat from Nubian goat is considered a secondary product (AOAD, 1990). 1.2.2 Desert goats These goats thrive in the arid dry areas of the Sudan, north of Lat.12 ◦ N (Wilson, 1991). These goats are related to the Sahel goats, which include many Saharan types from Egypt, Libya, Tunisia, Algeria and Morcocco (DAGRIS, 2007). It is well adapted to desert and harsh environments and hence called Sahel or desert goat. The body size is large to medium, both sexes are horned and being longer in the male, twisted and projected laterally. Ears are moderate in size and pendulous. The coat has short fine hairs with different colors, mainly grey with black and brown splashes (Mason, 1951; El Naim, 1979 and Kiwuwa, 1992). Mature body weight is 33 kg and 66 cm at wither height in adult female. Male liveweight range from 40 to 48 kg and wither height range from 69 to 83 cm (Gall, 1996). These goats are meat and skin producers (Devendra and Burn, 1983). The meat quality is good and dressing percentage is 49 % (Gaili et al., 1972). Age at first kidding is 7.5 – 11.1 months and kidding interval is 238 days (Gall, 1996). 7 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 1.2.3 Nilotic goats The dwarf equatorial riverain, goat is found in Southern Sudan, with similarities to the Small East Africa goat (Gall, 1996). It is compact and small in size and its live weight is 11- 25 kg. Males are beared and maned and the face profile is straight (Mason, 1951 and El Naim, 1979). Both sexes have small horns. Ears are medium in size. Colors are mixed but white and black are common. Nilotic goats can resist trypanosomiasis. There are three varieties of Nilotic goats, the Toposa (Mangla), Yei (Dinka) and Latuka Baria goat (Jonglli state) (Mason, 1951 and Muffarah, 1995). It is a meat type with low milk yield (Gall, 1996). Age at kidding is 10 months and kidding interval is 210 days (Gall, 1996). 1.2.4 Mountain goat (Taggar) Found in three distinctive mountainous areas, Nuba Mountains (Kordofan), Jebel Marra (Darfur) and Ingassana hills (Blue Nile). It is highly adapted to thrive in mountains, and exhibits active movements. Synonymous name is African Dwarf goat. About 4.5% of the goat population in the Sudan is Dwarf goats. Both sexes are horned and have short ears and neck. Males are beareded and maned. The goat colors are dark brown or grey brown ( El Naim, 1979 and Muffarah, 1995 ). The goat is of small size with short legs and height at withers is 56 cm. Adult body weight approximates to 20 kg for males and 18.5 kg for females (Elbukhary, 1998) In Rashad area, Elbukhary (1998) found age at first kidding to be 13.5 months and kidding interval 230 days. Males birth weight is 1.6 kg and 1.3 for females. Twining rate is 57%. Dressing percentage is 42.7 and 56.3 on slaughter and empty body weight basis respectively. 8 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 1.2.5 Baggara goat It dwells in Kordofan, reared by nomads and its population is about 800 thousands. It is considered a cross, between Desert and Nilotic breeds (Ageeb, 1992). Body weight is 26.4 – 30.8, heart girth 68.8 – 74.4 cm, height at withers 62.5 – 65.2 cm and body length 58.9 – 61.5 cm. Colors are variable ( Ageeb, 1992). Age at first kidding is 15.3 months, gestation length is 147 days and kidding interval is 234 days with a high twining rate of (65%). It is meat-type goat and the growth rate is 60.3, 40.8, 38.6 and 26.3 gm/day at 3, 6, 9 and 12 months of age respectively (Ageeb, 1992). 1.2.6 Crossbred goats Crossbreeding of goats is a breeding tool widely practiced throughout the Tropics. Some exotic breeds imported into the country (1976) were mainly Toggenburg, Saanen, Anglo- Nubian and Damascus. Khartoum and El- Gezira States were the first places where early numbers of these crosses emerged (Abo – El.Aazaim, 1996). Crossbreeding with local Nubian goats was meant for improving milk and meat production (Khalafalla and Sulieman, 1990 ). 1.3 Goat nutrition Good nutrition is a fundamental for livestock production. Feed accounts for the highest single cost of any goat production (Poore and LuginbuhI, 2002). Natural pasture (grasses, trees and shrubs) represent an important source for animal feeds. Range lands cover nearly 280 million feddans in the country, producing 77- 78 million tones, dry matter annually (Ahmed, 1998). Darrag (1994) found that range can not satisfy the requirements of the animals for fodder. Natural pastures are the principal 9 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 forage available for animals in the tropics but they are highly fibrous, lignified and of low protein content in the dry seasons (Elbukhary, 1998). Goats are selective browsers as they choose from large varieties of vegetation types (Engle, et al 2000 and Lillywhite, 2000). Their grazing habits enable them to survive the semi-arid harder conditions better than sheep or cattle (Rajapaksha et al., 2000). Browse yield is important in the Sudan because it forms a large proportion of the annual need of goats feed especially in the dry season. Goats also complement both sheep and cattle in marginal grazing lands. This allows goats to maximize the use of marginal pasture land as well as improved forage production systems ((Nye and Moore, (2004). Goats feed on a wide range of feeds and preferred plants high in leaves, seeds and with low cellulose i.e. rough, sparse pastures (Gulteridge and Shelton, 1994 and Campbell and Marshall, 1975). The goat has greatest range of adaptation and tolerance to many diseases except in the intensive production, where there may be parasitic infestations (Devendra and Burns, 1983). Goats consume relatively high dry matter intake, 3 – 5 percent of its body weight to maintain itself under conditions unlikely suitable for cattle (Green 1999). Goats respond well to increased quality/ quantity of feedstuff (Pinkerton, et al, 1991). 1.3.1 Nutrient requirements of goats Productive goats require nutrients for maintenance, growth, reproduction, pregnancy and production of meat, milk and hair. The nutrients that are essential in goat nutrition are energy, protein and their ratio, minerals vitamins and water. 1.3.1.1 Energy Energy probably is the best defined requirement of farm animals. Also, shortage of energy is translated immediately into a drop in production in dairy animals, and over 10 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 a longer period of time, other effects such as retarded growth, delayed puberty, and decreased fertility will become apparent. The ME requirement for maintenance (MEm) was 485, 489, 580, 489 and 462 kJ/kgBW0.75, and the ME requirement for gain (MEg) was 13.4, 23.1, 23.1, 19.8 and 28.5 kJ/gADG for preweaning, growing meat, growing dairy, growing indigenous and mature goats (indigenous and dairy), respectively. The MEm of mature Angora goats from multiple regression analysis (at 0 tissue gain and clean fiber growth) was 473 kJ/kg BW 0.75 ; ME requirements for tissue gain and clean fiber growth were 37.2 and 157 kJ/g, respectively (Sahlu et al ,2004) . For energy use by goats in grazing activities, NRC (1981) recommended the addition of 25% of the suggested MEm requirement with light activity, 50% with semiarid rangeland and slightly hilly conditions and 75% with sparsely vegetated rangeland or mountainous transhumance pasture. CSIRO (1990) indicated that with good grazing conditions, MEa is 10–20% greater than the activity cost in pen or stall environments and can be 50% greater with extensive conditions in which land is hilly and walking distances are great. Nsahlai et al. (2004a) evaluated the assumption of NRC (2001) that MEm is 20% greater for lactating versus non-lactating cattle; and resultant regression equations exhibited significant bias when used to predict values with the evaluation data set. Also, as discussed by Nsahlai et al. (2004a), it is likely that MEm is not constant throughout lactation, although insufficient data with goats were available to provide a justifiable recommendation for change. Luo et al. (2004e) reported a MEm of mature goats (462 kJ/kgBW 0.75), slightly lower than for growing indigenous and mature goats (489 kJ/kgBW0.75) and suckling goats (485 kJ/kgBW0.75). 11 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 It has been usually assumed that goats have similar energy requirements for maintenance as sheep being 725.8g SE/day/100 kg live weight. The energy requirement for live weight gain is 3 g SE/kg live weight gain (Williamson and Payne, 1978). Tolkamp et al. (1994) also did not find differences between sheep and goats in values obtained of parallel measures of fasting heat production made with adult castrated male goats and wethers using respiration chambers (Aguilera and Prieto, 1986) were 324 and 272 kJ/kg0.75 per day, respectively. This suggests a metabolic rate 20%higher in goats than in sheep (Aguilera et al., 1986 and Prieto et al., 1990). There are few reports available on the energy requirements of goats. Energy requirements in open range may increase several fold over those assumed for restrained animals. The social concern about maintenance and renovation of natural resources (sustainable development), and about animal welfare is growing up more and more, together with a renaissance of semi-arid extensive systems of animal production (Lachica and Aguilera 2005). They suggest that the use of tabulated values or the extrapolation of theoretical allowances obtained for other animal species may result in a great bias when predicting the energy needs of free-ranging goats in specific situations. Consequently, the application of a direct estimation approach should be encouraged whenever an accurate prediction of the additional expenditure of energy under grazing conditions is required with definite advantages over the use of tabulated values. 1.3.1.2 Protein Proteins are needed throughout life for growth and repair of the body and for synthesis of enzymes, hormones, mucin, milk, and hair. As for monogastrics, ruminants' protein requirement consists mainly of amino acids that are absorbed from the small intestine. However, these amino acids come from two sources, dietary i.e. post ruminal and microbial, utilizing soluble protein, nonprotein nitrogen, and ruminal ammonia (Mary and David, 1994). 12 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Different sources of protein vary in susceptibility to ruminal degradation and amino acid composition. The average concentrations of ruminally undegraded protein (UP) in blood meal, corn gluten, feather, fish, cottonseed and soybean meals is 80, 60, 75, 60 ,39 and 36% of total CP content (Preston, 2000). Fast growing ruminants have protein requirements, that exceed the amount provided by bacterial protein, and can benefit from supplemental protein, that has low ruminal degradability (ARC, 1980). The use of feedstuffs with low ruminal degradability in diets for high producing ruminants has received considerable attention in anticipation of enhancing performance (Keery and Amos, 1993). Most protein entering the small intestine is from microbial cells synthesized and feed not degraded in the rumen (NRC, 1996). Microbial protein synthesis is affected principally by ruminal concentrations of N containing compounds (Hespell, 1979) and the quantity of carbohydrates fermented (Rohr et al., 1986). When amino acid requirements are high, such as for rapidly growing young ruminants, ruminally produced microbial protein may not meet amino acid needs of the host. Protein level in the diet was found to be of importance in animal performance. Weston (1967) and Elliott and Topps (1963 c) suggested that dietary protein was the main limiting to voluntary feed consumption. Raising the level of dietary protein to lambs resulted in a linear increase of feed consumption and likewise feed chemical components up to 8% CP level. Beyond this protein level, the increase in feed consumption ceases linearity. Vipond et al. (1982) found in ewes significantly more feed consumption at higher CP supplementation (48%) than lower (13%). The same results were observed with cattle by Greathouse et al. (1974). Similarly, Weston (1971) found in lambs higher gains with higher protein diets. Voluntary feed consumption and the efficiency of feed utilization showed the same trend. Hinds et al. (1964) when increasing the level of 13 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 protein from 13.0 to 16.2% and from 15.4 to 18.4%, obtained a highly significant increase in live weight gain and a reduction in feed required per pound of gain. Ash and Norton (1987) found that increasing the protein content of the diet ( 11.3, 16.0 and 20.9% CP) resulted in significantly greater BW gains, largely promoted by increased intake rather than by enhanced feed efficiency. Effects of protein level on growth performance were studied by Atti et al. (2004) on goat kids. Animals were fed individually oat hay ad-libitum and one of three concentrates containing low, medium or high crude protein, 100, 130, and 160 g/kg dry matter respectively for 12 weeks. During the growth period (first 6 weeks), high CP diet gave greater growth rate than low and medium ones. Nitrogen requirements declined thereafter and goat kids didn’t need more than 13% CP. Feed intake and weight gain were the highest with medium CP level (130 g/kg DM), while nitrogen retention was favored by the highest CP level (160 g/kg DM). These results are in agreement with those reported by Tegene Negesse et al. (2001). These authors showed that growth rate and protein retention are optimum at 136 g CP/kg DM and 180 g CP/kg DM respectively. Nocek and Russell (1988) reported that if there is deficiency or insufficient utilization of CP, the digestibility of carbohydrate can be decreased. Low crude protein level increased the molar proportion of propionate and decreased molar proportion of butyrate and cellulytic protozoa population (Dayani et al., 2007). Aharoni et al. (1995) found no effect of dietary crude protein content on short chain fatty acid profiles in Friesian bull calves. Growing goats’ metabolizable protein for maintenance (MP m) was 3.07 g/kgBW0.75; metabolizable protein required for gain (MPg) was 0.290 g/g ADG for dairy and indigenous goats and 0.404 g/g ADG for meat goats. The MP requirement for 14 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 lactation was 1.45 g/g milk protein, equivalent to a milk protein efficiency of 0.69 (Sahlu et al., 2004). Increased dietary protein supply, specifically the increased supply of ruminal degradable protein, increases apparent digestibility of crude protein with warm-season grass hay or pasture (Olson et al., 1999; Bodine et al., 2000; Bodine and Purvis, 2003; Huntington and Burns, 2008). The apparent digestibility of CP improved as well with higher levels of dietary UP. This is consistent with Ferrell et al. (2001), who observed similar improvement in CP digestibility with soybean supplementation in lambs. Ruminants can be maintained and achieve some level of production on diets that contain virtually no true protein (Virtanen, 1966), however a requirement for N to support microbial growth remains (Hume et al., 1970; Mathison and Milligan, 1971). Urea recycling between body pools can be significant (Buttery and Lewis, 1982 and Nolan, 1993) and has been shown to conserve nitrogen when animals are consuming low protein diets (Egan et al., 1984 and Silanikove, 2000). Cocimano and Leng (1967) demonstrated that the urea space in sheep consuming low protein rations (35 g/kg CP) is significantly less than in animals on an optimal or high protein ration (135 or 170 g/kg CP) . Urine excretion is generally considered a major route of N loss if dietary CP is supplied in excess of requirements (Siddons et al., 1985; Bunting et al., 1987 and Freudenberger et al., 1994). 1.3.1.3 Energy /protein requirement The most critical item that influences feed quality is its digestible energy density and protein contents. Waghorn (1986) studied the effect of different protein/ energy intakes on nutritional and physiological parameters in young sheep. He stated that increasing either energy or protein intakes resulted in higher rates of gain, wool 15 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 growth, N retention, fat synthesis and higher plasma concentrations of insulin but lower concentration of Somatotropin. Lu and Potchoiba (1990) used growing Alpine and Nubian goats to quantify the influence of dietary energy and protein levels on daily DM intake and nutrient utilization for growth. Goats were fed on diets containing 2.46, 2.77 or 3.05 Mcal ME/kg plus 11.2, 12.7 or 15.1% crude protein respectively. DM intake decreased curvilineraly as dietary ME density increased. DM intake increased linearly as dietary CP level increased. The digestible crude protein requirements for maintenance are 45g/ 100kg live weight, while the energy and protein requirements for growth have been fairly well established. Luo et al. (2004d) utilized a database which included 80 treatment means representing 466 animals and concluded that metabolic body weight (W 0.75 ) is an appropriate scaler of goat energy requirements. When Sanjuva et al (1990) studied the effect of plane of nutrition on the growth of Indian Goddi male goats (at energy : protein 100:100, 115:115, 115: 85, 85: 115 and 85: 85) , he revealed that the growth rate increased significantly (p<0.01) with the energy level increases, irrespective of the protein level. Elfadil ( 2001) used different levels of protein and energy in the diet of Nubian goat kids, and found that the digestibility was better in those animals fed with high energy high proteins or high energy low proteins. Luo et al. (2004b) determined the metabolizable protein requirement for body weight gain to be 0.404 g/g of gain for meat goats and 0.290 g/g of gain for dairy and indigenous biotypes. These researchers stated that metabolizable protein intake may not have been more limiting to growth than ME intake. 16 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 1.3.1.4 Minerals requirement Mineral elements or electrolytes can be classified according to the relative amounts needed in the diet, namely macro and micro elements. Macro or major elements include calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), potassium (K) sulphur (S) and chlorine (Cl). Micro or trace elements comprise iron (Fe), iodine (I), copper (Cu), manganese (Mn), zinc (Zn) and cobalt (Co). Essential minerals are those which proved to have a metabolic role in the body. They activate enzymes which are essential co-factors of metabolic reactions or function as carriers of protein. They play role in regulation of digestion , respiration , water balance , muscle reaction , nerve transmission , skeletal strength or pH balance. Electrolytes can play role in protection against diseases as antagonists or synergists to other elements, or play a vital role in resistance, adaptation and evolution of new breeds and strains (Haenlein,1987). Goats require many minerals for basic body function and production, being provided as supplement or selected from the range. Major minerals likely to be deficient in the diet are salt (sodium chloride), calcium, phosphorus and magnesium. Trace minerals likely to be low in the diet are selenium, copper and zinc. (Poore and LuginbuhI, 2002). Excess minerals, such as phosphorus, copper and zinc, when supplied to the animal always result in excretion to the environment and eventually accumulates in the soil and groundwater (Jongbloed and Lenis, 1998). Producers are hence advised to calculate mineral supplement for goats in view of the dietary formula (Poore and LuginbuhI, 2002) or range plants mineral content (Ramirez et al., 2006). Most range plants had higher levels of minerals during summer. Ca, Mg, K, Fe and Mn contents in all plants and in all seasons can be sufficient for the requirements of grazing goats, while Na, P, Cu and Zn (with exception of few species) contents were marginally deficient in all seasons. However, different plants differ in their minerals 17 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 content significantly, and depending on their floral density, need may arise for supplementation during certain seasons. Also, interference between mineral levels during certain seasons needs to be considered. It appears that ration formulation for goats should include evaluation of the dominant available plants and consideration of their probable mineral contents during certain seasons for ration formulation (Ramirez et al., 2006). 1.3.1.4.1 Calcium Most calcium is extracellular at a 10mg % and exists in three states free ion (60%), bound to protein (35%) or in conjunction with organic acids such as citrate or with inorganic such as phosphate (5-7%) (Arthur and Martin, 1973). In general, during summer most plants had higher Ca than in other seasons. It seems that foliage from browse plants that grow in semi-arid regions of Texas, USA (Barnes et al., 1990) and Mexico (Ram´ırez et al., 2001; Cerrillo-Soto et al., 2004 and Ram´ırez-Ordu˜na et al., 2005) have enough Ca for optimal white-tailed deer and range goat performance, respectively 1.3.1.4.2 Sodium Sodium content in all shrubs was significantly different between seasons. D.texana and P. aculeata had the highest content (0.3 g kg−1 DM) and B. myricaefolia, C. pallida and H. parvifolia had the lowest (0.1 g kg−1 DM) (Ramirez et al., 2006). It appears that all shrubs can be considered as Na non-accumulators because they contain less than 2 gNa kg−1 DM (Youssef, 1988). Moreover, during all seasons all plants had lower Na content to meet the needs of a growing adult range goat. 18 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 1.3.1.4.3 Potassium High potassium content in evaluated shrubs (Ramirez et a.l, 2006) could reduce Na absorption of goats feeding these shrubs because it has been reported that elevated dietary K may decrease ruminal concentration and absorption of Na in sheep and steers (Spears and Harvey, 1987). It seems that a goat weighing about 50.0 kg BW consuming 2.0 kg day−1 DM of these shrubs could eat substantial amounts of K to meet their requirements for K for the whole seasons (Ramirez et al., 2006). Similar findings were reported by Greene et al. (1987), Ram´ırez et al. (2001), Moya-Rodr´ıguez et al. (2002), Cerrillo-Soto et al. (2004) and Ram´ırez-Ordu˜na et al. (2005) who evaluated K content in browse species growing in arid and semi-arid regions of the world. Potassium is primarily an intracellular cation, therefore its concentration in the serum is low and may not reflect body K status. Excretion is through the kidney in exchange for Na or H ions. Serum concentrations are responsive to acid-base balance. In animal acidosis (hyperkalemia), H ions move into cells, while potassium moves out. Serum level of K is regulated by renal excretion, which depletes body store. Hypokalemia may occur during alkalosis, as potassium moves into cells in exchange for H ions.( William, 2001). Although large amounts of potassium are required, this mineral is normally present in abundance in forage-based diets and is well absorbed. Possible signs of potassium deficiency include reduced feed intake, poor growth and reduced milk production. Severe deficiencies may cause emaciation and muscle weakness. Dietary potassium is also important in the maintenance of plasma sodium concentration. Levels of 0.5% of the diet for growing kids and 0.8% for lactating goats have been recommended, based on requirements for other ruminant species (NRC, 1981). 19 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 1.3.1.4.4 Phosphorus Phosphorus is found primarily in cells and bone, its serum concentration does not necessarily reflect body stores. Phosphorus moves into cells in exchange for hydrogen ions. Phosphorus is required for both soft tissue and bone growth. It plays an important part in nucleic acid synthesis, energy metabolism and acid-base balance. The normal serum phosphorus concentration is approximately 4.2 to 9.8 mg/dl for adult goats and 8.3 to 10.3 mg/dl for juveniles (Sherman et al., 1983). Clinical signs of phosphorus deficiency include slowed growth, pica, unthrifty appearance and decreased serum phosphorus levels with calcium. Temporary phosphorus deficiency in the adult can be met from body reserves, but with a prolonged deficiency milk production decreases. Animals fed a large quantity of concentrates, which typically contain 3 to 5 g P/kg, usually have adequate phosphorus intake, and in this instance a relative calcium deficiency may occur. In general, the Ca : P ratio in the diet should not be less than 1.2:1 (2:1 for males). Grazing goats rarely develop a phosphorus deficiency because of their tendency to browse varied and phosphorus-rich plants. All plants, in all seasons, had phosphorus contents that were not sufficient to meet adult goat requirements (Ramirez et al., 2006). Ramirez et al. (2001), Moya- Rodr´ıguez et al. (2002) and Ram´ırez-Ordu˜na et al. (2005) also reported that shrub species were deficient in phosphorus in all seasons. Ramirez et al. (2006) noted high Ca and low P content in shrubs resulted in an unusual wide range Ca: P ratios (from 9:1 to 63:1). However, it appears that browsing small ruminants (range sheep and goats) can sustain these high ratios without affecting phosphorus metabolism (Ram´ırez, 1999). 20 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 1.3.1.4.5 Magnesium The normal serum magnesium concentration for goats is 2.8 to 3.6 mg/dl. Magnesium deficiency may lead to anorexia or hyperexcitability. Serum calcium may be low because magnesium is required for the release and action of parathyroid hormone (Hoffsis et al., 1989).Goats can compensate somewhat for a dietary magnesium deficiency by decreasing output of both milk and urine. Barnes et al. (1990) reported high Mg contents (1.1–8.0 g kg−1) in 18 shrubs that grow in Texas, USA. Norton and Poppi (1995) found that some commonly used tropical legumes had Mg concentrations that meet ruminant requirements. Moreover, other studies have found that diets, from esophageal samples by range goats growing in north Mexico (Cerrillo-Soto et al., 2004), or browse plants from northeastern (Ram´ırez et al., 2001) and north western Mexico (Ramirez – Orduria et al, 2005) had sufficient amount of Mg to meet requirements of adult range goats. 1.3.1.4.6 NaCl salt Sodium is the most abundant extracellular cation. It is excreted primarily by the kidney. Increases (hypernatremia) occur with dehydration. Decreases (hyponatremia) occur with dietary deficiency, rapid Na loss e.g. diarrhea, vomiting or renal diseases. Ordinary diets are more apt to be deficient in sodium than in chloride. Goats that lack sodium may lick dirt. They also may show reduced growth and feed intake and reduced milk production with increased butterfat concentration (Schellner, 1972). Goat milk from European breeds contains approximately 0.4 g/kg sodium. 1.3.1.4.7 Zinc Zinc is required for the formation of certain metallonezymes. The major metabolic abnormalities associated with Zn deficiency are caused by a blockage of protein synthesis, DNA synthesis and cell division. Zinc deficiency in goats was 21 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 reported to cause parakeratosis, joint stiffness, excessive salivation, swelling of feet and deformities of the hooves, small testes, and low libido. Reduced feed intake and weight loss also occur. Appetite was said to return within few hours after zinc supplementation. 1.3.1.5 Vitamins requirement Vitamins are needed by the body as micronutrients. The vitamins most likely to be deficient in the diet are A, D and E. For ruminants, all other vitamins are either formed by ruminal bacteria or are synthesized in the body tissues in adequate quantities to meet needs. (Poore and Luginbuhl, 2002). Carotenes are precursors of vitamin A in green leafy forages which are converted into the body to vitamin A. Long-term stored forages or weathered forages undergo vitamin A deterioration, and hence goats consuming that should be fed supplemental vitamin A in a vitamineral mix, or should receive vitamin A injection on drastic depletions (Poore and Luginbuhl, 2002). Animals confined to barns especially during the winter, may become deficient in vitamin D. Animals should have frequent access to sunlight to enable vitamin D synthesis in the skin, or they should receive direct supplemental vitamin D. Vitamin E is abundant in fresh high quality forages, but it is apt to deteriorate on storage. Generally, providing some vitamin A, D and E either by periodic injection or preferably in the mineral mix is good for ruminants (Poore and LuginbuhI, 2002). 1.3.1.6 Water requirement Water is the commonest and least expensive nutrient, but also limiting to production, growth and the general performance of animals at insufficiency (Poore and luginbuhl, 2002). Tropical goats are adapted to water intermittence or shortages, hence many factors affect water intake. Water intake is higher on high physiological demand e.g. late gestation and during lactation (Carles, 1983). Water intake increases with 22 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 increase in ambient temperature and double at 40oC (Maglad et al., 1986). Increasing dry matter intake, nitrogen, minerals and salts in feeds also increases water intake (Devendra and Mcleory, 1982). Goats are efficient animals in the use of water. Goats generally have slow body water turnover, and water intake in goats vary considerably between 0.68 – 4.4 kg/ day and is correlated to dry matter intake (Devendra and Mcleory, 1982). 1.4 Feed intake Voluntary feed intake is defined as a weight eaten by an animal or group of animals on free access to food, being a complex mechanism centrally controlled with some local gastrointestinal reflex arcs (Forbes, 1995; Baile and Mc Laughlin, 1987). Ruminants increase their feed intake in response to an increase in demand for energy and protein or both (Kenedy and Milligan, 1987). The composition of a diet determines the animal's voluntary intake. Nutrient imbalance can reduce feed intake as when ammonia or an amino acids form the first limiting nutrient (Leng et al., 1977). El Fadil (1995) found that feed intake increased as the energy level increased and reported values of feed intake by desert goats as 3.68, 4.22 and 4.54 Kg. per week for high, medium and low dietary energy levels. Seymour and Polan (1986) found that dairy cows on a high energy diet ate less dry matter and lost more body weight than cows on low energy diet, whereas milk yield and composition were no different. For herbivores, the productivity escalates with digestible energy intake i.e. voluntary feed intake, which is positively correlated with nutrient content and digestibility of forage (Skarpe and Bergstorm, 1986). Blaxter (1967) concluded that total energy consumption and ultimate performance of the animal are functions of voluntary feed intake. Intensive finishing requires high daily gain which increases the efficiency of feed utilization by adopting high feed intake through 23 ad libitum feeding Ahmed, Aisha B. M. , Ph.D Thesis, 2008 or elevating nutrient concentrations by feeding high proportion of concentrates (Owen and Gray, 1992), but to a diminishing return of feed intake and efficiency (Montgomery and Baumgardt, 1965; Conard, 1966; Waldo, 1967; Geay and Robeline, 1979 and Hicks et al., 1990). Volume of dry matter intake varies with the composition of a diet. With roughage diets (<65% D. M. D.), large bulk limits feed and energy intake (Mertins , 1985). When D.M.D. is above 65%, total intake of energy remains reasonably constant for finishing cattle. Hence, feed intake declines as energy concentration increase (Owen and Gray, 1992). Following, the addition of a small portion of roughage to an all concentrate diet will increase the voluntary feed intake (Wise et al., 1965; Boweres, 1968 and Preston and Willis, 1975). The physical form of the diet affects feed intake (Cottyn et al., 1971), as well as crude fiber content (Debrahanders et al., 1978). McCullough (1970) reported pelliting supplemented with either concentrates or dried grasses to increase dry matter intake. Supplemental undegradable protein yielded an increase in feed intake and rate of gain compared to the unsupplemented lambs (Kempton and Leng, 1978 and Hassan and Bryant, 1986). When digestible energy is less than 2.5 MCal/kg, Dinius and Baumgardt (1969) observed that feed intake in sheep is to be limited by gutfill. Environmental factors such as high or low temperature, wind and humidity can alter feed intake (Owen and Gray, 1992). High environmental temperature reduces rate of feed intake and hence affects maintenance requirements and efficiency of animal weight gain (Ames and Ray, 1983; Deagan and Young, 1981). Ruminants are sensitive to the ruminal heat produced by fermentation (Forbes, 1980). Summer total dry matter intake by Egyptian sheep and goats was significantly lower than during winter and spring (El Mouty et al., 1988). Offensive smell or dusty feed affects the rate of feed intake. Intolerable smell is of volatile materials given off by unpalatable pasture 24 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 plants, and it will be rejected by the animal without tasting (Preston and leng, 1987). Dust in feed is irritable to nose and eyes and decreases feed intake inversely. 1.5 Body weight Growth is measured in terms of live weight per unit of time in addition to changes in body conformation and measurement (Pomeroy, 1955). Pattern of relative growth of body components are not affected by the nutritional experience and that variation in body composition are largely examined in terms of differences in body weight (Wallace, 1948 and Tulloh, 1963). High plane of nutrition accelerates live weight growth well to the genetic capabilities of the individual animal (Brook and Vincett, 1950 and Pomeroy, 1955). Wilson (1976) in southern Darfur, Sudan; observed indigenous kids to have a growth rate of 87 g/ day for the first 3 months growth phase and 65 g/ day for the second 3 months growth phase. Ageeb (1992) reported in both male and female kids of Baggara goats of South Kordofan, Sudan higher daily gains during the first 3 months. The average daily gains at different stages of growth were 60.3 ± 22.7, 40.8 ± 18.1, 38.6 ± 22.7 and 26.3 ± 3.6 g/day at 3, 6, 9 and 12 months of age respectively. This is a normal growth curve in which rates of gain tend to diminish with increase in age. Devendra (1983) in Malysia reported average daily gain in native goat breed on extreme range as 18 g/day up to more than 200 g/day for improved goat breed on high plane of nutrition. The growth rate of Indian male goats increased significantly as energy level increased irrespective of protein levels when fed on different ratios of protein and energy (Sanjuva et al., 1990). The feed conversion ratio (FCR) is defined as the amount of food required by an animal to produce one unit of live weight. Breed type, sex and plane of nutrition are factors affecting the FCR and the postnatal growth of the animal. Rate of live weight gain for tropical goats was reported by Devendra and Burns (1983) as 0.5 kg per week. 25 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Average F.C.R. of 10.76 to 22.52 Kg dry matter/ Kg weight gain was reported in intensively fed Sudan Desert goats on different levels of feed (Osman, 1984). Babiker et al. (1985) reported a weekly weight gain for Sudan Desert goats intensively fed from weaning to 7.5 months of age to be 0.5 Kg for entire and 0.38 Kg for castrates. Babiker et al. (1985) reported an average F.C.R. of Sudan Desert goats intensively fed for 126 days from weaning to slaughter at 30 Kg live weight to be 5.06 and 6.56 Kg DM/Kg gain for entire and castrated kids respectively. Bello (1985) fed entire Sudan Desert goats and their temperate crosses with a diet of 12.75 MJ/Kg DM. Weekly weight gain was 0.55 Kg and 0.7 Kg for entire desert male kids and their temperate crosses respectively. He also reported FCR at 8.39 and 7.06 for his tested kids respectively. Different proportions of concentrate (high -H, medium- M and low -L) to roughage in the performance of Sudan Desert goats were studied by El Amin et al. (1990). They observed no significant difference on the daily gain of the animals. They also reported FCR of 8.3, 9.0 and 11.8 respectively. Entire male Desert goat kids were fed by Ibrahim (1996) three energy levels, 12 (high energy), 10 (medium energy) and 8 MJ/Kg DM (Low energy). Difference in the final live weight and the rate of weight gain per week for the three treatments was highly significant for the high and medium dietary energy levels. The F.C.R. was 7.6, 11.95 and 24.06 for the high, medium and low energy levels. 1.6 Goat health 1.6.1 Clinical examination A complete clinical examination consists of history taking, physical, environmental and laboratory inspections. 1.6.2 Physical examination It is often diagnostically useful to observe a group of goats from a distance prior to disturbing them for "hands – on" examination. The animals should be observed at 26 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 rest, while eating or drinking and during spontaneous and forced movement. Body condition, mental attitude, and the status of the superficial lymph nodes should be noted. The temperature, pulse, and respiration should be recorded. The normal body temperature of goats is usually reported in the range of 38.6 – 40.0 0C (101.5 – 104.0 0F). However, the body temperature of a normal Angora goat with a full fleece on a hot, humid day can reach 40.30 C (104.50 F) or higher, and goats of lighter body weight are more likely to have a higher temperature when exposed to sun than bigger goats (Mc Gregor, 1985). The pulse can be measured by stethoscope over the heart or by digital palpation of the femoral artery. Normal pulse rate ranges from 70 -90 beats per minute in resting adults, but can be double that in young, active kids. Fetal heart rates up to 180 bpm have been recorded by ultrasound. It may be useful to assess respiratory rate both at rest and after exercise. Any abnormalities of respiration should also be noted including flaring of nostrils, extension of head and neck, grunting, abdominal press and so forth. The heart is heard most audibly over the left thoracic wall at the fourth intercostal space. Heart rate varies considerably in goats with age and level of activity. Mean heart rates for small numbers of goats at different ages have been reported from India (Schaer et al., 1989). Barbari goat kids from birth to 15 days of age had mean heart rates per minute of 255± 15 and 209± 6 from 16 days to 1 month of age. By 1 to 6 months of age, mean heart rates had decreased to 142 ± 6 and to 125 ± 9 between 6 and 12 months. Goats 1 to 3 years of age had heart rates of 126 ± 5 and goats 3 to 5 years of age, 126 ± 7. In one American study, of 100 male goats to 1.5 years of age, the mean heart rate was 96% with a range of 70 to 120 (Toussaint, 1984). In a second American study of 8 adult females of mixed breed, the mean was 105 with a range of 90 to 150 (Roudebush and Sweeney, 1990). 27 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 The normal respiratory rate at rest is approximately 10 to 30 breaths per minute (kids 20 to 40 /min). In addition, many normal goats will pant and a respiratory rate of 270 per minute has been reported for goats held at 104° F (40°C). A goat with a long winter coat will certainly breathe rapidly if brought into a warm and humid room. Notably not every goat that breathes rapidly or harshly has respiratory disease. Different rates of heat loss and different partition of retained energy between protein and fat has to be due to a different metabolizable energy (ME) utilization for maintenance or/and for growth. The values for ME requirement for maintenance and ME net efficiency for energy retention estimated by Sanz Sampelayo et al. (1995) were of the same magnitude as those obtained by others for kid goats (Jagusch et al., 1983 and Sanz Sampelayo et al., 1988) and lambs (ARC, 1980 and Degen and Young, 1982). The increase in ambient temperature through the morning and towards the afternoon may explain the significant rise in respiratory rate, pulse rate and rectal temperature for all the treatment groups studied. However, respiration rate showed greater proportional changes than pulse rate and rectal temperature because the homeothermic animals initially react to stress by enhancing the thermo-regulation mechanism, such as respiration rate, to avoid an increase in body temperature These findings are in agreement with reports on variable dietary energy level intakes in other breeds maintained in semi-arid hot environments (Naqvi, 1987; Hooda and Naqvi, 1990). The lower values for respiration rate, pulse rate and rectal temperature recorded in animals subjected to restricted feed may be attributed to their low metabolic rate during the energy deficiency (Maurya et al, 2004). The energy requirements for maintenance also vary with environmental conditions (such as temperature, humidity, and wind) and with exercise. The heat of fermentation normally lost during digestion helps to maintain body temperature of 28 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 ruminants in a cold environment. In fact, a goat on a high roughage diet has the benefit of more internal heat production to keep it warm. Animals without active rumen function must shiver to maintain body temperature. For this reason a 'goat coat is often beneficial to an animal off feed because of illness or surgery (Mary and David, 1994). Examination of body regions and systems include mucous membranes, oral cavity, eyes, nares, ears, and horns; examination of the neck, examination of the chest, examination of the abdomen, examination of the limbs, examination of the reproductive system and mammary glands. In goats, the character of the skin and haircoat is a good indicator of general health. A rough, dry unglossy coat, excessive dander or flakiness, and failure to shed out in the spring are all suggestive to poor nutritional status, parasitism or other chronic disease. The hair or fleece should be parted and the skin examined for lice, ticks, fleas (in tropics), nodules, swellings, crusts, eczema, necrosis, neoplasia, photosensitization and sun burn and focal or regional alopecia. 1.6.3 Environmental examination Overcrowding can facilitate transmission of lice and pneumonia and predispose to herd outbreaks of enteric diseases, some of which can assume chronic forms. Poorly drained paddocks and barns can contribute to foot problems and coccidiosis; Chronic weight loss can be related to the way animals are fed. If young animals can climb or defecate in feeders, then fecal contamination promotes the spread of coccidiosis. Keyhole-type feeders common in goat dairies may promote the rupture of head and neck abscesses during feeding, causing contamination of feed and spread of caseous lymphadenitis. Inadequate feeder space in either keyhole-type or trough-type feeding systems may deprive individual animals, low in the social pecking order of adequate feed intake. 29 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 1.6.4 Laboratory examination 1.6.4.1 Blood and plasma parameters Mean blood volume as a percentage of body weight is approximately 7.0% with a range of 5.7% to 9.0% (Fletcher et al.,1964) and Brooks et al., 1984) or 70.0 to 85.9 ml/ kg b.w. (Jain, 1986). Blood volume increases in responses to increased altitude (Bianca, 1969). The mean specific gravity of whole blood is 1.42 with a range of 1.04 to 1.50 (Fletcher et al., 1964 and Brooks et al., 1984). The osmotic pressure of the serum colloids is 300 mm Hg. Mean plasma volumes range from 4.2% to 7.5% of body weight, or 53.0 to 60.2 ml/kg b.w. (Jain, 1986). Mean plasma specific gravity is 1.022, with a range of 1.018 to 1.026. Anemia results from RBC loss, excessive RBC destruction (regenerative anemia) or depressed RBC production (non regenerative anemia), may be due to nutritional deficiencies, iorn, vitamin B12 and folic acid . The mean corpuscular volume (MCV) is an indication of overall RBC size. It increases in regenerative amemias and may decrease in states of iron deficiency. MCHC indicates the concenteration of Hb per unit volume of RBCs. Reduced MCHC indicate iron deficiency. An elevated MCHC indicates hemolysis or laboratory error. The decreases in hemoglobin (Hb) and packed cell volume (PCV) that occur during the first month of life may be due to iron deficiency anemia associated with a milk diet. The decrease can be prevented in kids by administration of 150 mg of iron as iron dextran at birth (Holman and Dew, 1990). Seasonal changes are also noted in erythrocyte parameters, with greater red blood cell (RBC), Hb, and PCV values in late summer and fall than in winter and spring. Male goats tend to have higher RBC counts than females. Pregnancy has little effect on erythrocyte parameters, but PCV can decrease during the first 5 months of laciation. 30 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 The goat has the smallest erythrocyte of domestic mammals, with a diameter of 3.2 to 4.2 microns. As a result, standard methods of determining the PCV may overestimate it by as much as 10% to 15% because of inadequate centrifugation time. For the microhematocrit method, centrifugation or a minimum of 10 minutes at 14,000 G is recommended for accurate results. The standard Wintrobe method cannot generate sufficient relative centrifugal force to completely pack RBCs even when centrifugation time is extended. As much as 20% of plasma can be trapped with erythrocytes (Jain, 1986). The large size of newly released erythrocytes was reflected in a progressive increase in the MCV, which was highest from 25 to 29 days after bleeding, but did not always exceed the normal range of MCV reported for the species. Therefore, the MCV must be interpreted carefully in establishing the presence of regenerative anemia. Hemoglobin and PCV levels return to before bleeding levels by 5 weeks. The mean white blood cell (WBC) count of the goat is generally reported to be 9000 cells/µl in the range of 4000 to 14 000. However, total WBC counts and differential cell counts may vary significantly with age. Lymphocytes numbers begin to decline again and remain roughly equivalent to neutrophil numbers throughout adulthood. However, in a field study with sampling of 1000 goats in Mexico, eosinophil counts in kids younger than 7 weeks of age averaged 0.5% of the WBC count, but 4.3% in adults (Earl and Cartanza, 1980). Guldelines for interpretation of caprine leukograms have been suggested by Coles (1986). A WBC count more than 13 000 /µl constitutes leukocytosis and a counts less than 4000 /µl, leucopenia. A neutrophil count greater than 7200/µl represents neutrophilia and a count less than 1200 /µl, neutropenia. More than 100 band neutrophils/ µl constitutes a left shift. Lymphocytosis is interpreted as a lymohocytes count greater than 9000/µl and lymphopenia by a count less than 2000/µl. Monocytosis is represented by monocyte 31 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 count more than 550/µl and eosinphilia by an eosinophil count more than 650/µl. Inflammatory responses in the goat often produce a neutrophilia with total WBC counts in the range of 22 000 to 27 000 /µl. The maximum WBC count reported in a goat is 36300/µl observed in association with kidney abscess (Jain, 1986). A mature neutrophilia is often seen associated with stress and chronic infections, particularly when abscesses develop as in caseous lymphadenitis or mastitis. Acute bacterial infections can produce a moderate to severe neutrophilia with some degree of left shift. Acute severe coccidiosis in young kids is a frequent cause of marked neutrophilia and left shift. The mean platelet count in the goat is generally considered to be 500 000/µl, with a range of 340 000 to 600 000/µl (Mitruka and Ramnsley, 1981 and Lewis, 1976). Lower platelet counts were identified considerably in goats, with an average count of 116 000/µl during the first 2 weeks of life, decreasing to 28 000/µl by 1.5 years of age and stabilizing at an average 62 550/µl by 2 years of age (Holman and Dew, 1965). 1.6.4.2 Clinical chemistry Enzyme AST is found in many tissues, including liver, skeletal muscle, cardiac muscle and erythrocytes. LDH is found in most tissues, including liver, muscle, kidney and erythrocytes. Creatinekinase (CK), an isoenzyme of creatine phosphokinase (CPK) is found in skeletal muscle, cardiac muscle and brain. Enzyme CK increase in muscle damage. Hepatic parenchymal disease that causes a disruption of hepatocytes can lead to measurably increased serum levels of a number of intracellular hepatic enzymes in goats (Kaneko, 1980 and Carnier et al., 1984) Increases in aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) are not liver – specific and also result from muscle cell damage. Basal levels of sorbitol dehydrogen (SDH) in goat liver and serum are much higher than those reported for cattle 32 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 and sheep. Concentration of liver – specific enzymes are generally higher in acute liver disease than chronic liver disease and may be within normal limits in the later stages of prolonged hepatic disease, so careful interpretation of laboratory values in conjunction with clinical findings is essential. The range of mean total serum protein concentrations reported in goats is from 6.75 to 7.53gm/dl with concentration in individual goats ranging from 5.9 to 8.3 gm/dl (Fletcher et al., 1964; Mitruka and Rawnsley, 1981 and Melby and Altman, 1976). Total protein consists of albumin and globulin fractions. Albumin is synthesized by the liver and catabolized by peripheral tissues. It functions maintenance of OP and as carrier for transporting various hormones, ions, and drugs. It increases with dehydration and decreases with the decrease in protein intake, malnutrition or starvation. Globulin portion of serum proteins includes the immunoglobulins and various transport proteins. The hepatic insufficiency leads to hypoalbuminemia. Normal serum albumin levels in the goat are reported in the range of 2.7 to 3.9 g/dl (Kaneko, 1980). Sources of serum glucose include dietary intake, liver glycogenolysis and gluconeogensis. Hepatic dysfunction can also cause hypoglycemia. Normal blood glucose level in the goat was reported in the range 50 to 75 mg/dl (Kaneko, 1980). As in other species, the kidney serves multiple functions, including water and electrolyte balance, nutrient conservation, maintenance of normal blood pH levels and regulation of nitrogenous wastes. The kidney also has endocrine functions (Nolly and Fasciolo, 1972). Recently, the excretion of inulin, creatinine, sodium sulfanilate (SS) and phenolsulfonphthalein (PSP) has been evaluated to assess caprine renal function (Brown et al., 1990). Bilirubin results from the breakdown of heme. Hemoglobin from erythrocytes is the primary source of heme, but myoglobin and some heme-containing enzymes also 33 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 contribute. Total bilirubin concentration in the serum of normal goats is generally reported to be in the range of 0.0 to 0.1 mg/dl (Kaneko, 1980). Increased bilirubin concentration in the range of 0.2 to 0.8 however, have been reported in normal pygmy goats, values varying with both age and sex (Castro et al.,1977) As in cattle and sheep, circulating bilirubin levels increase only modestly in the face of severe generalized hepatic disease (Sen et al., 1976). The most dramatic increase in serum or plasma bilirubin in the goat is due to hemolytic crises rather than liver dysfunction (Wasfi et al., 1976). Creatinine clearance was determined not to be a reliable measure of glomerular filtration rate (GFR) in goats, primarily because of the existence of a tubular secretory mechanism for creatinine in the goat. Urea is produced from ammonia exclusively by the liver. Urea is excreted primarily by the kidneys. Increase with dehydration, renal disease, circulatory impairment, mild increase with a high-protein diet. Decrease may occur with dietary protein restriction. Normal blood urea nitrogen (BUN) levels are in the range of 10 to 28 mg/dl. Serum creatinine is derived from the breakdown of phosphocreatine, an energy storage molecule found in the skeletal muscle. Creatinine is found in the skeletal muscle and the primary excretion is through the kidneys. However, some may be lost through the gastrointsinal tract. Hence creatinine concentration is related to the muscle mass. Heavily muscled or well-conditioned animals may have serum creatinine at the highest end of the reference range. Conversely, creatinine concentration may be low in animals having marked loss of muscle mass. Small amounts of creatinine also may be absorbed from meat in the diet. Creatinine increases with dehydration and muscle wasting. Normal creatinine levels range from 0.9 to 1.8 mg//dl and normal uric acid levels from 0.33 to 1.0 mg/dl. Breed, sex and age variations in these normal parameters have not been identified in goats. 34 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Serum levels are regulated by the interaction of parathyroid hormone calcitonin, and vitamin D. excretion occurs mainly through the kidneys. The normal serum calcium concentration for goats is approximately 9.0 to 11.6mg/dl (4.5 to 5.8 mEq/L) 1.7 Wasting diseases The loss of weight without obvious signs of disease is known as wasting or ill thrift, which is a common syndrome in goats. While individual goats may lose weight for one or more known reasons, the abnormally thin goat is often a sentinel of serious herd infectious, parasitic or management origin problems. Ill thrift in mature animals is taken to mean that a loss of weight in individual goat has occurred and the goat is abnormally thin. In growing animals it may also mean that the animal has lost weight, or alternately, that the rate of weight gain is less than expected from past experience, known breed standards or in comparison with other animals on the premises. The numerous causes of weight loss include nutrition-related causes, chronic affections being caused by viable causative agents and miscellaneous other causes including dental ruminal and neoplasia (Mary and David, 1994; Merck, 2004 and Bene and Bene, 2002). 1.7.1 Nutrition-related Causes Nutrition-related causes of chronic weight loss fit in either of two categories, primary causes resulting from the unavailability of appropriate feed or specific nutrients and secondary causes leading to the inability of animals to apprehend or intake feed even when available (Mary and David, 1994; Merck, 2004 and Bene and Bene, 2002). 1.7.1.1 Primary nutritional problems In extensive systems, feed availability can be curtailed by sustained, severe weather conditions such as drought or heavy snow cover, and also by overgrazing, over35 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 stocking, or failure to provide supplemental feed when nutrition requirements are not being met. In confinement systems, inadequate feeder space can lead to weight loss. This should become apparent if animals are observed during feeding. In any management system, specific nutritional deficiencies may be caused by inappropriate feedstuffs, unexpected feed shortages, unbalanced rations, inexperience with livestock feeding and occasionally negligence (Mary and David, 1994; Merck, 2004 and Bene and Bene, 2002). Regarding specific deficiencies, inadequate energy and protein levels are most commonly involved in cases of primary nutritional weight loss (Tilton and Warnik 1964). Cobalt deficiency may be a specific cause of progressive emaciation with no localizing signs in goats. Goats grazing cobalt-deficient pastures will show loss of appetite, rough hair coat, weakness, muscle wasting and anemia and may die after several weeks to months. Copper deficiency can cause inadequate weight gains in growing goats (Anke, M. et a.l,1972). In stations where forage quality is extremely poor, with little or no fresh green forage available, hypovitaminosis A may contribute to progressive emaciation ( Schmidt, H., 1941). 1.7.1.2 Secondary nutritional problems A variety of ailments must be considered which could limit the animal's ability to obtain or use feed. These include developmental or behavioral problems. Even when feeder space is adequate, goats with a low social standing in the herd hierarchy may be barred from feeding by more dominant goats. Goats with marked brachygnathism may be unable to prehend and masticate efficiently and will not do well under extensive management. In the oral problems, the excessive or loss of teeth, a common cause of thin ewe syndrome, can also occur in goats though it is less frequent, this is because goats are more likely than sheep to browse in range and pasture and therefore less likely 36 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 to wear away teeth by grazing low to the ground on abrasive soils. (Mary and David, 1994; Merck, 2004 and Bene and Bene, 2002). Water intake can also diminish as worn teeth are more sensitive to cold temperatures. Animals with dental attrition become progressively weaker and emaciated and can succumb to secondary disease processes, particularly pneumonia and pregnancy toxaemia. Contagious ecthyma as a soft tissue infection is common in goats worldwide and can produce painful, scabby legions on the lips that persist from 3 to 6 weeks or longer if secondary bacterial infections occur. These lesions can impair feed intake and lead to weight loss. Animals fed in confinement can readily adapt to sudden blindness if surroundings are unchanged. Grazing animals on sparse rangelands, however, probably depend heavily on sight for adequate feed intake. Angora goats with excessive hair covering of the face, an inherited trait, graze inefficiently because of impaired vision. They may become thin and often succumb to secondary disease problems. Locomator problems of the foot and leg can interfere with efficient grazing or produce sufficient pain to keep animals recumbent instead of standing at the feeders. Weight loss may precede outward signs of lameness due to reluctance to ambulate and eat. (Mary and David, 1994; Merck, 2004 and Bene and Bene, 2002) 1.7.2 Chronic affections 1.7.2.1 Viral causes Caprine arthritis encephalitis virus (CAEV) is the arthritic form of the viral infection which generally affects variably the animal mobility and hence associated with weight loss. This form most often appears clinically between 1 and 2 years of age with great variability in the progression and severity of signs. Viral contagious ecthyma was cited above causing oral problems. Foot and mouth disease temporarily affects movement and prehension due to viral injuries in the foot and mouth. Rinderpest and 37 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 rinderpest-like disease of goat peste des petits can cause pronounced weight loss and debilitation in goats during the prolonged convalescent periods that follow acute diarrheal disease (Mary and David, 1994; Merck, 2004 and Bene and Bene, 2002) Pulmonary adenomatosis or jaagsiekte is a neoplastic transformation of the lung possibly caused by a retro-virus distinct from CAEV. It is primarily a sheep disease but has been reported in goats. The disease produces a syndrome of progressive dyspnea and weight loss with pronounced nasal discharge over a period of several months. 1.7.2.2 Bacterial causes Any prolonged infection may contribute to progressive debilitation and weight loss. It is very likely that paratuberculosis (Johne's disease) is frequent but undiagnosed cases show progressive weight loss in adult goats. Caseous lymphadenitis is caused by Corynebacterium pseudotuberculosis . Tuberculosis is uncommon in goats but sporadic cases continue to be reported. Mycobacterium bovis is the most common cause, but M. avium and M. tuberculosis also occur. Melioidosis infection is caused by soil saprophyte Pseudomonas pseudomallei. Pasteurella pneumonia of goats is widespread and often becomes chronic due-to failure of early detection coupled with inadequate therapy. Peritonitis can occur secondary to a number of conditions, these include rumenitis resulting from grain overload, migration of liver flukes through abdominal organs, administration of irritating drugs intraperitaneally, rupture of internal abscesses and as sequelae to abdominal surgery or septicaemia. Salmonellosis and enterotoxemia present most often as causes of acute, frequently fatal, enteritis or toxemia. 1.7.2.3 Parasitic causes Both ecto and endoparasites can contribute significantly to progressive weight loss in goats, either primarily or in association with malnutrition or concurrent disease. 38 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Gastrointestinal parasitism include coccidiosis, nematodiasis, cestodiasis, tapeworms, trematodiasis, and fascoila spp. Internal parasites are of universal importance in goats, although the species will vary according to the climate, management system and breed of goat. It seems goats are more susceptible to internal parasite than sheep and cattle are. This is perhaps because they are browsers by nature. Some gastrointestinal parasites are nematodes (haemonchus contortus), cestodes (Moniezia spp.), Trematodes (paramphistomum spp.) and Protozoa (coccidian, including Eimeria spp).Of all the gastro-intestinal parasites that affect goats, haemonchus contortus is by far the most important species. The main symptoms of parasitic infection are weight loss, reduced feed intake, reduced milk production, pale mucous membranes, anaemia, diarrhoea and some times death. The effects of cestodes such as Moniezia spp are relatively minor, except in kids. (Urquhart et al., 1996 and Ballweber, 2001) Ecto or external parasites can contribute to ill thrift when infestations are severe and concurrent diseases are present. Biting lice such as Damalina caprae may cause irritation to affected hosts leading to reduced feeding efficiency. Among the mange mites affecting goats are the sarcoptes (Urquhart et al., 1996 and Ballweber, 2001). In tropical regions, heavy infestations of goats with fleas of the genus Ctenocephalides can cause anorexia, anemia, weight loss, and even death. Goat kids are most severely affected. Of the blood parasites only trypanosomes were known to cause chronic body loss (Urquhart et al., 1996 and Ballweber, 2001). 1.7.3 Miscellaneous causes A wide variety of poisonous plants may affect goats on pasture or range. Plant toxicities show all of the range, from acute to chronic symptoms. Often plant toxicities are subclinical (Mathews, 1940 and Cao, et al., 1992). 39 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Progressive weight loss accompanied by progressive abdominal distension suggests the presence of gastrointestinal foreign bodies. Consumption of plastic trash bags is common where rubbish disposal is casual and goats forage in urban areas. These foreign bodies can lead to partial gastrointestinal obstructions, chronic indigestion, abdominal distension and weight loss. Tumors or neoplasia are an unusual finding in goats and only rarely cause progressive emaciation (Mary and David, 1994). 1.8 Under nutrition Undernutrition is one of the major setbacks of animal production in the tropics (Kallah et al., 2000 and Collins-Lusweti, 2000). A seasonal weight loss of up to 40% in beef and mutton herds can be expected (Clariget et al., 1998) in extensive systems with lack of supplementation, as demonstrated by Jordan and Le Feuvre (1989). Periods of under nutrition due to low plane of nutrition or malnutrition create stress which often produces bodyweight loss (Meyer et al., 1962). Meyer et al. (1965) noted that sheep lost 6.1 Ib body weight when fed 70% ad libitum straw and 13.7 Ib body weight loss when fed on straw alone. Similarly Hadjipanyton et al. (1975) found loss of body weight from 38.8 kg to 31.2 kg body weight during12 weeks of straw feeding to lambs. The straw intake decreased with time and was accompanied by increase in the rate of bodyweight loss due to nutrients deficiency in straw coupled with reduced energy. Reduced feed intake decreases bodyweight or rate of growth. Reduced growth rate occurred when sheep were fed at 52% of the control, and the sheep fed at 20% of the control lost 5.5 kg bodyweight during 42 days. (Meyer and Clawson, 1964). Substantial reduction in live weight of Rommeny ewes was observed when their feed intake was restricted to 0.3 Ib/day, and ewes body weight loss was 20 Ib during the first 21 days of feed restriction. During the following 21 days, further reduction in live 40 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 weight (12.8 Ib) was reported (Hight and Barton, 1965). Initial live weight was reduced 33-39% when fat Marino ewes were fed diminishing quantities of a mixture of lucerne chaff and oats for 50 days. Under feeding was accompanied by considerable depletion of tissue reserve (Panarito, 1964). Low protein was reported to produce marked bodyweight loss (Meyer et al., 1965). Energy deficiency was assumed to be a limiting factor for bodyweight gain, whereas both protein and energy deficiencies were assumed to cause severe bodyweight losses (Alden, 1968a and Tilton and Warnik, 1964). Digestibility of feed governs the voluntary intake. Hay voluntary intake was more than twice that of straw due to low digestibility of the straw (Campling et al., 1961). Milford and Minson (1966) observed that tropical grass intake fell when the crude protein percentage was less than 7%. Intake of hay increased markedly by sheep when dietary protein supply was doubled to 2.6g (Eliot, 1967). Likely with protein, non protein nitrogen can affect the same. Campling et al. (1963) noted an increase oat straw intake by 40% when urea (75 g) was infused of in the rumen. Van Soest (1965) showed that fiber content inhibites intake of roughages of high cell wall contents (50-60%). As demonstrated by Prior et al. (1981) and Goetsch et al. (1998), ruminant serum amino acid concentrations seem to be a consequence of feed consumption, consequently different serum free amino acid concentrations could also be expected as a result of undernutrition. Serum amino acid concentrations are expected to increase as a consequence of protein breakdown caused by undernutrition (Bergen, 1979). In adequately fed dairy cows, variations of serum free amino acid concentrations after feeding, tend to show an increase in Ala, Glu, Gly, Arg, His, Ile, Leu, Met, Phe and Val, the maintenance of Ser, Pro, Lys, Thr and a decrease in Tyr and Asp (Ndibualonji et al., 1997). A 27 h fasting period in sheep has been reported to cause an increase in Ile, Leu, Phe, Lys, Tyr and Glu, maintenance of Thr, Met, His, Arg, Asp, Ser and Ala and a 41 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 decrease in Gly concentrations (Cross et al., 1975). These results are partially contrary to those of Heitmann and Bergman (1980) in sheep, where underfed animals had higher concentrations of Gly, Leu, Ile and Val than those observed in normally fed animals, with no differences obtained in concentrations of Ala, Glu, Ser, Arg, Thr, Lys, Phe and Tyr. A longer fasting period of 6 days was applied in sheep by Pell and Bergman (1983) and resulted in an increase in the concentrations of Asp, Ile, Leu, Lys and Tau, while Thr, Glu, Pro, Gly, Ala, Val, Phe and Orn had similar concentrations to those observed in normally fed sheep. Undernutrition significantly affects several muscle characteristics (Bedi et al., 1982; Crouse et al., 1984; Mosoni et al., 1999 and Ameredes et al., 1999) mainly as a result of the increased degradation of tissue mass (Wassner et al., 1977) and the decrease in protein synthesis (Ogata et al., 1978; Fong et al., 1989 and Van Eenaeme et al., 1998). Increasing whole protein degradation levels are expected to influence not only whole myofibrillar protein breakdown, but also at the level of each one of the myofibrillar proteins (Fong et al., 1989), as observed in the chicken (Iñarrea et al., 1990) and rabbits (Samarel et al., 1987). The trial done by Almeida et al. (2004) aimed at defining the serum free amino acids and myofibrillar protein profiles in Boer goat bucks, hence contributing to the establishment of the physiological components of undernutrition in a species where information on this subject is lacking. In ruminants, a negative relationship has been clearly established between the level of intake and digestibility, due to a higher retention time of digesta in the rumen when intake decreases (Galyean and Owens, 1991). Most experiments in this area were conducted at levels of intake higher than at maintenance. However, when animals are fed at under-maintenance level, the effect of a decrease in intake is variable. Digestibility may remain constant (Grimaud and Doreau, 1995) or even decrease (Grimaud et al., 1999). In these cases, an increase in the retention time of particles 42 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 occurs in the rumen, which does not result in an improved digestibility. It is, therefore, likely that a drop in digestion at low intake could be due to limitations of microbial activity. Knowledge on the origin of a disturbance in digestive processes in underfed animals is lacking. Moreover, it is of practical interest to know if animals are able to adapt to feeding deficiency. Blaxter and Wainman (1964), Graham (1964b) and Blaxter (1961) all noted in sheep decreased digestibility coefficients of the major nutrients when the plane of nutrition was increased. Decreasing intake resulted in a substantial decrease in digestibility. This was opposite to other observations on the effect of level of intake on digestibility (Galyean and Owens, 1991), but in accordance with recent results obtained at levels of intake lower than maintenance. This decrease in digestibility has been especially shown with forage diets in less drastic feeding conditions (Grimaud et al., 1998, 1999) and with a concentrate diet given in very small amounts (Gingins et al., 1980). In other experiments, the low intake involved no variation (Michalet-Doreau and Doreau, 2001) or an increase in digestibility (Kabré et al., 1995). When animals were underfed, retention time of digesta was very long. This did not avoid a drop in digestibility and confirms that when intake is very low, digestibility cannot be improved by a longer retention time of digesta in the rumen. Energy insufficiency may affect growth and productivity of animals more than any other nutrient (Blaxter, 1956). Wilson and Osbourn (I960) stated that previously restricted animals must be fed ad libitum to high plane of nutrition to take advantage of their compensatory growth potential. Recovery after a period of gross under nutrition in young cattle has been reported by Waldrop (1966) and Harte (1968). Other workers (Waters, 1908,; Eckles, 1946; Brook and Vincett, 1950 and Crichton, Aitken and Boyne, 1959) noted that prolonged undernutrition in the first 8-12 months of life in cattle may cause permanent stunting of growth. Bohman (1955) noted that cattle under 43 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 one year of age were slower on compensation after energy insufficiency period and they needed longer refeeding periods than mature cattle subjected to similar treatments. 1.9 Compensatory growth Because of their adaptability to a wide range of sources of feed, adult goats do not lose condition during the dry season (Devendra and Mcleroy, 1987). For growing goats, gross under nutrition is known to decrease growth rate and if it is severe it may lead to loss in weight. The enhanced growth noted or the higher growth rate of a previously (pre-pubertal) underfed animal following refeeding has been called Compensatory Growth (Bohman, 1955 and Osborne and Mendel, 1915). The subject of compensatory growth has been reviewed by Wilson and Osbourn (1960), Lawrence and Pearce (1964) and Allden (1970). Compensatory response of previously underfed animals on refeeding is governed by several factors, age of the animal at the beginning of growth restriction, nature of nutrients restricting growth, severity and duration of growth restriction and plane of nutrition on refeeding. Under nutrition in the earlier stages of growth is more detrimental to an animal than is restriction at a later stage. Consequently, the age at which an animal is subjected to under nutrition may be as important as the severity of under nutrition (Wilson and Osbourn, 1960). Compensatory or catch-up growth is a rapid growth spurt that occurs in a wide range of mammals, including humans, domestic animals and birds (Wilson and Osbourn, 1960; Ashworth and Millward, 1986; Mersmann et al., 1987; Summers et al., 1990 and Marais et al., 1991). Nutrient composition in diet is one of the factors influencing an animal’s ability to recover from the effects of undernutrition, among which the most attention has been paid to protein restriction (Wilson and Osbourn, 1960). A 19% body weight loss in ewes subjected to restricted diet could only be compensated to 17% during the re-alimentation period of the same duration (Maurya et 44 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 al., 2004). The higher weight gain during re-alimentation after restricted diet is in agreement with O’Donovan (1984); Naqvi and Rai (1991) and Oldham et al. (1999). This may be ascribed to lower maintenance requirement (Thomson et al., 1979). The overall loss in body weights remained approximately 5% in animals subjected to restricted diet, followed by grazing/re-alimentation. Sheep fed ad libitum on a 60% recovered fully to their live weight by 73 days ad libitum feed intake (Ledin, 1983). Gaili (1975) observed no compensatory growth on rehabilitation of growth restricted lambs between birth to one month of age and 1-2 months of age. Coop and Clark (1955) noted that sheep at one year of age, previously underfed, with 13.5 kg difference in body weight from the controls, recovered completely on grazing for 20 months. Donald and Allden (1959) observed that post-weaning undernutrition did not affect the productivity in Merino wethers. It was stated that the more severe the restriction, the greater the initial rate of gain after realimination, and during a period of under nutrition animals maybe fed at rates above or below maintenance energy requirements. (Wilson and Osbourn, 1960). Feed restriction on the growth performance of kids was studied by Toukourou and Peters (1999). Restricted kids had lower daily gains than the control, but on subsequent realimination, the restricted kids showed compensatory growth and caught up the controls in body weight after 10 weeks. Rompala et al. (1985) found that steers realiminated after a 70 day period of live weight constancy exhibited compensatory growth between 200 – 300 kg live weight, after which they exhibited normal growth patterns to the completion of the trial. However, Rayan et al. (1993a) found that steers exhibited compensatory growth over a much wider weight range (350 -600 kg) spanning a time period of approximately 11 months. Gomez et al. (1999) studied the effect of long term feed restriction on metabolism and tissue composition of adult goats. They found that plasma insulin did not differ 45 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 between the treatments, but the final live weight, blood glucose, carcass and hepatic tissue protein deceased. The liver and muscle DNA increased significantly with restriction. The results suggested the capacity of goats to adapt to long term under nutrition and the importance of hepatic and muscle tissues as sources of metabolic energy. The composition of the diet eaten during realimination has a significant effect on the ability of animal to demonstrate compensatory growth. Fontana et al. (1992) had shown that the protein might be a limiting nutrient during the recovery after a period of restriction. Rayan et al. (1993a) restricted steers for 89 days starting at 250 kg, after which they were realiminated on a high quality diet (0.9 and 11.7 MJ ME/Kg 16.2% crude protein DM basis) given ad libitum. This diet was fed until the steers reached approximately 600 kg. These steers compensated completely. The restricted cattle had greater feed intake than the controls for about 140 days (day 100-240 post restriction) offering support to the results of Graham and Searle (1975), who reported that greater feed intake might be the main mechanism responsible for long term compensatory growth. The amount of feed consumed during realimination may have an effect on compensatory growth. Rayan et al. (1993a) found that during realimination, steers that were previously restricted had greater feed intake than non-restricted control animals for approximately 140 days. For the last two thirds of 330 day period the extra growth of the realiminated cattle could be explained entirely on the basis of higher feed intake. Increases in feed intake and daily gain after a period of feed restriction had been reported by other workers (Owen et al., 1971 and Donker et al.,1986). Bikker et al. (1994) found compensatory gain and feed e,fficiency to improve with increased feeding level in the realimination period, stressing the importance of the dietary conditions during realimination. 46 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 CHAPTER TWO MATERIALS AND METHODS The study comprises three experiments: 2.1 Nutritional and health profile of debilitated Nubian goats 2.1.1 Experimental animals Eighty adult (2-4+ years old) apparently normal female Nubian goats, of a debilitated condition (one third or less of the average normal adult weight, located at Fitaih Al Agaleein suburb, south to Khartoum, were surveyed in the field using a survey form (Appendix 1). 2.1.2 Data collected 2.1.2.1 Liveweight Liveweight was recorded to the nearest 0.01 kg using a pressure digital ground balance. 2.1.2.2 Management Owners were explained for the extent of management entities (Feed, water, shelter and remedies) offered to their goats. 2.1.2.3 Clinical examination The general health condition of the goats was assessed by monitoring pulse, respiration and temperature plus observations of gait, alertness, skin and faeces. Mouth, buccal cavity and udder were examined plus abdominal palpation for presence of foreign bodies. 2.1.2.4 Blood Only apparently healthy goats were used to drain blood. Twelve goats, randomly selected, were subjected to drain of blood samples. A blood haemogram was done. 47 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.1.2.5 Serum Sera were prepared and analyzed for metabolic indicators glucose, total protein, albumen, bilirubin, creatinine and urea; electrolytes Na, Ca, K, P and serum enzyme AST, CK and LDH activities were also measured. 2.1.2.6 Internal parasites Twelve animals were randomly selected for faecal examination for internal parasites, using quantitatively the McMaster counting technique. Eggs per gram faeces up to 500 were considered mild, 2000 moderate and above that were considered heavy. 2.2 Protein realimentation of adult debilitated Nubian goats 2.2.1 Experimental animals and housing Twelve adult (2-4 years old) apparently normal female (non-lactating) Nubian goats, of a debilitated condition, as selected for Experiment 1, were bought from Fitaih Al Agaleein area to be used experimentally. The goats were rested, watered, eartagged and allowed one week adaptation to the Plate 1. Housing facilities of experimental goats premises and the experimental control ration. At the end of the adaptation period the goats were weighed to the nearest 0.01 kg to mark the initial body weight. Goats were randomly weight-distributed to 4 groups (A, B, C and D) of three heads each. Group A was designated as control; the other three were test groups. Each goat was kept separately in a pen (1x2 m.) with sandy floor and thatch roof (Plate 1). The pens Plate 2. Feeding trough of experimental goats were adequately ventilated and equipped with watering and feeding facilities (Plate 2). 48 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.2.2 Experimental rations A control diet (A) and three test diets (B, C and D) were formulated (Table 1). Smaller to large quantities and concentrated to roughage characteristics of ration ingredients were milled weighed and mixed manually in respective priority. The control diet furnished 8% CP and 6 MJ ME per kg. Control goats were ofered wheat bran and green Abu 70 fodder daily at 150gm and 3kg / head respectively. The test rations B, C and D provided variable crude protein content 12, 14, and 16% at an increasing protein /energy ratio respectively with a constant energy (9MJ ME / kg) value. Table (1). Percent composition (as-fed basis) and calculated chemical composition (dry- matter basis) of experimental rations fed to goats at constant energy (9MJ ME / kg) and diffrent level of protein for 11 weeks. Protein % Ingredient Dura Cottonseed cake Wheat bran Groundnut hulls Abu-70 NaCl Total Groups 8 A 12 B 14 C 16 D 25 75 100 40 10 15 33 2 211 30 20 20 28 2 211 23 35 20 20 2 211 93.13 7.88 1.85 28.75 46.97 7.68 5.62 1.40 93.44 12.22 3.12 26.33 47.36 4.42 8.55 1.42 93.41 13.85 3.55 25.52 46.08 4.68 8.55 1.58 93.44 15.62 4.12 23.39 45.52 4.79 9.35 1.67 Calculated analysis Dry matter CP% Ether extract Curde fiber Nitrogen-free extract Ash Energy (MJ ME/kg) P/E ratio 49 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Individual feeding and watering was ad libitum. Salt-licks were available to all groups throughout the experimental period. A fixed amount of the green forage Sorghum bicolor (Abu 70) was offered to test groups at the rate of 200 g /head twice weekly. Experimental feeding was continued for 11weeks. 2.2.3 Data collected 2.2.3.1 Performance All animals were weighed weekly at 7.00 a.m. before feeding to the nearest 0.01 kg using a livestock balance of maximum load 180 kg. The initial body weight was recorded on the first day of the experimental feeding. Average body weight and weight gain for each group were determined weekly throughout the experimental period. Daily feed intake by each goat was calculated by difference between refusals and the amount offered daily. Data on total feed intake and live weight gain was used to calculate the FCR. The general health condition of the animals was closely observed. 2.2.3.2 Blood Heparinized blood samples were withdrawn from the jugular vein fortnightly at 7.00 am, and were analyzed on the same day for RBCs count, Hb concentration, PCV, WBCs count and their cell differentials lymphocytes, neutrophils, basophils, oesinophils and monocytes. 2.2.3.3 Serum profiles Non-heparinized blood samples were withdrawn from the jugular vein fortnightly at 7.00 am, and sera were prepared. Sera samples were analyzed for concentrations of metabolites glucose, total protein, albumin, creatinine and enzyme AST activity and minerals P and Ca. 50 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.3 Energy realimentation of adult debilitated Nubian goats 2.3.1 Experimental animals and housing Twelve adult (2-4 years old) apparently normal female (non-lactating) Nubian goats, of a debilitated condition, as selected for Experiment 1, were bought, prepared and adapted to the premises and the experimental control ration as done with Experiment 2. At the end of the adaptation period the goats were weighed to the nearest 0.1 kg to mark the initial body weight. Goats weight-distribution, grouping and housing facilities were provided as in experiment 2. 2.3.2 Experimental rations A control diet (A) and three test diets (B, C and D) were formulated (Table 2) the same technique explained in experiment 2. The control diet energy and protein values were the same as in experiment 2. Control goats were fed wheat bran and green Abu 70 fodder daily at 150 g and 3kg / head respectively. The test rations B, C and D provided variable energy content 8, 10 and 12 MJ ME / kg at a decreasing protein /energy ratio respectively with constant 12% crude protein. Individual feeding and watering was ad libitum. Salt-licks were available to all groups throughout the experimental period. A fixed amount of the green forage Sorghum bicolor (Abu 70) was offered to test groups at the rate of 200 g /head twice weekly. Experimental feeding was continued for 11weeks. 2.3.3 Data collected 2.3.3.1. Performance Animals weighing, weight gain and daily feed intake were taken the same way with experiment 2. Data on total feed intake and live weight gain was used to calculate the FCR. The general health condition of the animals was closely observed. 51 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Table (2). Percent composition (as-fed basis) and calculated chemical composition (dry- matter basis) of experimental rations fed to goats at constant protein (12%) and variable energy for 11 weeks. Ingredients Energy MJ/Kg Groups Dura Cottonseed cake Wheat bran Groundnut hulls Abu-70 NaCl Total 6 A 25 75 100 8 B 30 12 17 39 2 211 10 C 60 06 10 22 2 211 12 D 90 02 02 04 2 211 93.13 7.88 1.85 28.75 46.97 7.68 5.62 1.40 93.59 12.19 3.22 30.55 42.81 4.81 7.55 1.66 93.15 12.17 2.90 18.41 56.03 3.64 9.78 1.24 92.72 12.33 2.65 5.94 69.34 2.46 11.8 1.04 Calculated analysis Dry matter CP% Ether extract Curde fiber Nitrogen-free extract Ash Energy (MJ ME/kg) P/E ratio 2.3.3.2 Blood Heparinized blood samples were withdrawn from the jugular vein fortnightly at 7.00 am, and were analyzed on the same day for RBCs count, Hb concentration, PCV, WBCs count and their cell differentials lymphocytes, neutrophils, basophils, oesinophils and monocytes. 2.3.3.3 Serum Non-heparinized blood samples were withdrawn from the jugular vein fortnightly at 7.00 am, and sera were prepared. Sera samples were analyzed for concentrations of metabolites glucose, total protein, albumin, creatinine and enzyme AST activity and minerals P and Ca. 52 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.4 Methods 2.4.1 Haematological methods 2.4.1.1 Blood sampling The blood samples were collected every two weeks at about 7.00 am from the jugular vein, using a 10 ml plastic disposable syringe. Ten ml of blood were obtained from each animal into clean dry heparinized vacotainers for haematological parameters which were evaluated on the same day of collection (Schalm, 1965). During the collection of samples the animals were kept quiet, as the excitation may lead to significant change in the composition of the blood (Kelly, 1984). The area from which the blood was drawn was cleaned with alcohol. 2.4.1.2 Red blood cell count (RBC) Red blood cells were counted with an improved Neubauer haemocytometer (Hawksly and Sons Ltd. England). Formal citrate (3 gm sodium citrate, 1 ml conc. formaldehyde, 100 ml distilled water) was used as a diluent. The red blood cells diluting pipette was filled according to the procedure described by Schalm (1965). All erythrocytes in the 4 corners of the chamber and the center squares were enumerated, the total was multiplied by 104 and expressed in millions per cubic mm of blood. 2.4.1.3 White blood cell count (WBC) White blood cells were counted with an improved Neubauer haemoycytometer (Hawksley and Sons Ltd. , England). Turk’s solution (1 ml glacial acetic acid, tinged with gentian violet, 100 ml distilled water) was employed as a diluent. The white cell diluting pipette was filled according to the procedure described by Schahm (1965). Enumeration was of the white cells was achieved by counting all leucocytes in the 4 leucocytes counting squares, the total was multiplied by 50 and expressed in thousands per cubic mm of blood. 53 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.4.1.4 Differential leukocyte count The percentage of neutrophils, monocytes, esinophils and basophils were determined microscopically from a count of 100 leukocytes in thin, Giemsa stained blood smear (Kelly, 1984). Giemsa stain was prepared by transferring 3.8g of Giemsa powder to a dry bottle, 250 ml of methanol were added to the stain and mixed well, and then 250 ml of glycerol were added and mixed well. For use, the prepared Giemsa stain was diluted 1:10 with distilled water. The blood smear was prepared freshly blood. The blood was spread using the spreader slide, then the smear was dried at room temperature and fixed by placing in absolute methyl alcohol for 5 minute. The smear was covered by stain for 15 minute, then the smear was rinsed well in distilled water and allowed to dry. The blood film was examined using the oil immersion lens (X 100). 2.4.1.5 Packed cell volume (PCV) Fresh blood samples were centrifuged in a microhaematocrit centrifuge (Hawksley and Sons Ltd., England) for 5 minutes and PCV percentage was read off on the microhaematocrit reader provided with the centrifuge. 2.4.1.6 Haemoglobin concentration (Hb) Haemoglobin concentration was determined by the cyanmethaemocytometer technique using a haemoglobinometer. The method is based on the conversion of haemoglobin by mean of Drabkin’s solution (0.2 gm potassium cyanide, 0.2 gm potassium ferricyanide and 1 gm sodium bicarbonate per liter distilled water) to cyanmethaemoglobin. The concentration was measured in gm/100 ml of blood. 2.4.1.7 Red cell indices 2.4.1.7.1 Mean corpuscular volume (MCV) MCV was calculated from RBC number and PCV values as follows: 54 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 MCV (m3) = PCV x 10 RBC in million/mm3 2.4.1.7.2 Mean corpuscular haemoglobin (MCH) MCH was calculated from RBC count and Hb values as follows: MCH = Hb (g/dl) RBC in million/mm3 2.4.1.7.3 Mean corpuscular haemoglobin concentration (MCHC) MCHC was calculated from PCV and Hb values as follows: MCHC % = Hb (g/dl) X 100 PCV % 2.4.2 Chemical methods 2.4.2.1 Determination of serum constituents Jugular blood samples were collected from animals every two weeks and allowed to clot. Serum was separated and stored at -20ºC until analyzed. Spectrophotometer, Merck Mega, Version 0.6, 1995 (E. Merck, Darmstadt, Germany) was used to analyze serum enzyme activities, serum metabolites and serum electrolytes. 2.4.2.1.1 Serum enzyme activities 2.4.2.1.1.1 Glutamate oxalacetate transaminase (Aspartate amino transferase, Laspartate: 2-oxoglutarate aminotransferase, E.C. 2.6.1.1, GOT; AST) Serum GOT activity was measured colorimetrically (Schrockert and Basseler, 1971) using test kit (Merck, Darmstadt, Germany). Test principle Aspartate aminotransferase catalyses the reversible transfer of an amino group from aspartate to α-ketoglutarate forming glutamate and oxalacetate: L-aspartate + α-ketoglutarate GOT 55 L-glutamate + oxalacetate. Ahmed, Aisha B. M. , Ph.D Thesis, 2008 The oxalacetate produced is reduced to maltate by maltate dehydrogenase (MDH) and NADH. Oxalacetate + NADH + H+ MDH Maltate + NADP The rate of decrease in concentration of NADH is proportional to the catalytic concentration of GOT present in the serum sample. Protocol Non-haemolytic serum was incubated with a buffered mixture of L-aspartate and α-oxoglutarate at 37ºC for 12.6 minutes. The initial absorbance was recorded 1 minute after addition of the serum sample and at 1minute interval thereafter for 3 minutes. The mean absorbance per minute (Δ A/minute) was recorded and used for the calculation of enzyme activity. The absorbance was read at U.V. wavelength 340 nm. and enzyme activity was calculated as follows: µ/L = ΔE × 3489 (Where E= emission) 2.4.2.1.1.2 LDH ( Lactate dehydrogenase ) Serum LDH activity was measured by using commercial kit (Merck, Darmstadt, Germany) according to Sharma and Datta (1971). Test principle It is measured by the lactate librated from decreasing NADH by the enzyme activity. Pyruvate + NADH + H LDH Lactate + NAD Protocol None-haemolytic serum was mixed with NADH + phosphate buffer pH 7.5 and sodium pyruvate. The mixture was incubated at 37ºC for12.6 min. The enzyme activity was read at U.V. wavelength 340 nm. The enzyme activity was calculated as follows: µ/L = ΔE × 3489 (Where E= emission) 56 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.4.2.1.1.3 CK (Creatine kinase ) Serum CK activity was measured according Paterson (1971) by using commercial kit (Merck, Darmstadt, Germany). Test principle The measurement of the rate of increase in NADPH librated is directly proportional to the CK enzyme activity. Creatinine phosphate + ADP ATP + D-glucose HK CK creatinine + ATP ADP + D-glucose-6-phosphate D-glucose-6-phosphate + NADP G-6-PDH D-gluconate-6-phosphate + NADPH + H+ Protocol Non-haemolytic serum was mixed with the substrate mixture in sufficient buffer. The reaction mixture contains the substrates, enzymes and cofactors necessary for the coupling reactions that are ADP creatinine phosphate and magnesium acetate for reaction 1., glucose and hexokinase for reaction 2., and glucose-6-P dehydrogenase and NADP for reaction 3. It also contains AMP to inhibit the action of adenylate kinase present in red cells and glutathione to increase CPK activity that may have been lost in storage. The mixture is buffered to pH 6.7 with imidazole acetate buffer. The reaction was read at wavelength 340 nm. and CK activity was calculated as follows: µ/L = ΔE × 4932 (Where E= emission) 57 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.4.2.1.2 Serum metabolites 2.4.2.1.2.1 Blood sugar level Serum glucose values were determined using enzymatic kits provided by Plasmatic Laboratory Product, Ltd. Test principle Glucose level was measured according to the method described by Giterson et al. (1971). Glucose + O2 + H2O Gluconate + H2O 2H2O2 + phenol + 4-amino-antipyrine red chinonimin + H2O Protocol Dilute enzyme reagent (GOD + POD + 4-amino-autipyrine) was mixed with buffer (phosphate buffer, pH 7.5 + phenol). None-haemolytic serum was mixed with the reagent solution and the mixture was incubated at 37ºC for 15 min. The absorbance was read at wavelength 500 nm against the reagent blank and calculated as follows: U/L = Δ A sample / Δ A standard × standard concentration (100 ml/dl) (Where A= absorbance) 2.4.2.1.2.2 Total protein Total serum protein was measured by a colorimetric method using a commercial kit (Randox Laboratories Ltd., U.K.) Test principle Colorimetric determination of total protein in serum is based on the biuret reaction. The serum protein reacts with copper sulphate in the presence of sodium hydroxide. The Rochelle Salt (K-Na-tartarate) contained in the biuret reagent is utilized 58 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 to keep the formed cupric hydroxide in solution which gives the blue colour. The intensity of the colour produced is proportional to the amount of protein in the sample. The absorbencies of the sample (A sample) and of the standard (A standard) were read against the reagent blank in the spectrophotometer at a wavelength of 545 nm. The total serum protein concentration (C) was calculated as follows: C (mg/dl) = A sample X concentration of the standard A Standard 2.4.2.1.2.3 Albumin Serum albumin was estimated quantitatively by the bromocresol green indicator method (Doumas et al., 1971). Test principle Measurement of serum albumin is based on its quantitative binding to the indicator 5,5-dicromo-o-cresolsulphonaphthaline (bromocresol green, BCG). Protocol None-haemolysed serum was mixed with a buffered BCG reagent and incubated at 20-25ºC for 5 minutes. The absorbance of the sample and that of the standard were measured against the reagent blank at a wavelength of 630 nm and albumin concentration was calculated as follows: g/L = Δ A sample / Δ A standard ×standard concentration (6 g%) (Where A= absorbance) 59 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.4.2.1.2.4 Urea Serum urea concentration was estimated by an enzymatic colorimetric method using a kit (Randox Laboratories Ltd., U.K.). Test principle Ammonia and carbon dioxide are produced when urea is hydrolysed by urease Urea + H2O urease Ammonium carbonate + CO2 Ammonium ions react with phenol and hydrochlorite to give a coloured complex. Protocol The serum was mixed with a buffered urease solution and the mixture was incubated for 10 minutes at room temperature. The hydrochlorite solution was added and mixed and the contents were incubated at room temperature for 15 minutes. The absorbency of the sample (A sample) and of the standard (A standard) were read against the blank at a wave length of 546 nm and the concentration (C)of urea was calculated as follows: C (mg/dl) = A sample X concentration of the standard A standard 2.4.2.1.2.5 Creatinine Serum creatinine concentration was measured according to Cook (1971) using test kit (Merck Mega, Darmstadt, Germany). Test principle Creatinine reacts with picric acid under alkaline condition to yield a coloured complex. The intensity of the developed colour is proportional to the concentration of creatinine in the reaction mixture. 60 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Protocol None-haemolytic serum was mixed with LiOH and Li picrate. The creatinine activity was measured at wavelength 524 nm. The absorbance of sample was read as mg/dl. 2.4.2.1.2.6 Total bilirubin Serum total bilirubin concentration was measured according to Van Roy et al. (1971) using a diagnostic kit of Merck Mega, Darmstadt, Germany. Test principle Bilirubin reacts with diazotized sulfanilic acid to form an azo dye, which is red in neutral and blue in alkaline solution, whereas, the water-soluble bilirubin glucouronides react directly, the free indirect bilirubin reacts only in the presence of an accelerator. Protocol None-haemalytic serum was mixed with diazotized sulfanilic acid after the addition of accelerator (caffeine + sodium benzoate + sodium acetate). A blue azobilirubin is found in alkaline Fehling solution (potassium sodium tartrate + sodium hydroxide solution). The direct bilirubin was read exactly 5 minutes after the addition of serum at wavelength 548 nm. The absorbance of the sample was read against the sample blank as follows: Concentration of direct bilirubin = A × 14.0 mg/dl = A× 240 µmol/L (Where A= absorbance) 61 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 2.4.2.1.3 Determination of serum electrolytes 2.4.2.1.3.1 Sodium Test principle Serum sodium concentration was determined by flame photometry as described by Varly (1967). Protocol Diluted serum (1:100) was passed under controlled condition as a very fine spray in the air supply to a burner where the solution evaporates and the salt disassociates to give neutral atoms. Light of characteristic wavelength was emitted and passed through a specific fitter for sodium ion to a selenium cell and the amount of current product was read on a galvanometer. Changes in the galvanometer reading for the sample against that of low standard concentration of NaCl (14 µmol/L) were recorded and sodium values were calculated in mEq/l as follows: Sodium concentration (mEq/l) = (T/S) × 140 Where T = test ; S = low standard. 2.4.2.1.3.2 Calcium Serum calcium concentration was determined by a colorimetric method using a commercial kit (Randox Laboratories Ltd., U.K.). Test principle Calcium ions form a violet complex with chromogen (-O-cretholphthalein complex one-8- hydroxyquinoline hydrochloric acid) in an alkaline medium (2-amino-2methyl-propan-1-01). 62 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Serum was mixed with a buffered reagent and the absorbance of the sample (A sample) and of the standard (A standard) were measured against a reagent blank at a wave length of 578 nm and calcium concentration ( C ) was calculated as follows: C (mg/dl) = A sample X concentration of the standard A standard 2.4.2.1.3.3 Potassium Test principle The method described by Varly (1967) for the determination of serum potassium is based on the same principle of flame-photometry as in serum sodium determination. Protocol The sensitivity of the instrument was varied in order to use the same dilution of serum (1:100) for both sodium and potassium. The galvanometer was adjusted to zero using the blank and adjusted to 100 using a high concentration standard of KCl (7 mmol/l). Changes in the galvanometer reading for the sample against that of the low standard concentration of (5 mmol/l) were recorded and potassium value was calculated in mEq/liter as follows: Potassium concentration (mEq/L) = (T/S) × 5 Where T = test ; S = low standard. 2.4.2.1.3.4 Phosphorus Determined by a colorimetric method using a commercial kit (Randox Laboratories Ltd, U.K.). 63 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Test principle In nitric acid phosphate forms a coloured complex with molybdate and a reductant. Serum was added to trichloroacetic acid for deproteinization, then the supernatant was added to the reductant and molybdate and the absorbance of the sample was read against a blank at a wavelength of 405 nm. Phosphorus concentration (C) was calculated as follows: C (mg/dl) = 42.2 X A sample. 2.5 Proximate analysis of experimental diets Samples of experimental diets were approximately analyzed, on dry-matter basis, for moisture, ash, crude protein, crude fiber, ether extract (fat) and nitrogen free-extract by the procedure described by the Association of Official Agricultural Chemists (AOAC, 1980). Results were expressed as percentage composition. 2.6 Statistical analyses Results of the survey data were expressed as percentages. Growth curves were drawn lineary as regression of weight on time. Mean test values in blood and serum were compared to the control using the unpaired students' t-test (Snedecor and Chochran, 1967). 64 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 CHAPTER THREE RESULTS 3.1 Nutritional and health profile of debilitated Nubian goats In the goat herds survey (Table 3), eighty female goats raised as dairy, at age range 1-4 +years were surveyed. Half of the herds in the area were medium in size (1020 heads). Table 3. Goat herds survey at Fitaih El Agaleein, 25km south of Khartoum. Domain Herd size (from which the sample was selected) Ecotypes Age Sex Body weight Production purpose Herd manager Site Item < 10 10-20 20-50 > 50 Nubian Local crosses Foreign crosses 1-2yrs 2-4yrs > 4yrs Male Female 20-30kg 30-50kg Milk Meat Dual Owner Other Other with pay Non spcefic Farm Indoors Range Number of heads 14 40 26 0 74 6 0 7 32 35 0 80 57 11 80 0 0 61 0 18 0 0 11 67 % 17% 50% 33% 0 93% 07% 0 10% 43% 47% 0 100% 83% 17% 100% 0 0 77% 0 23% 0 0 14% 86% The Nubian goats were 93% of them and only 7% were local crosses. About 83% of the surveyed goats had body weighed range 20 – 30 kg. Herds were mostly (77%) 65 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 managed by their owners or with pay to others (23%). Herds were 86% managed in the range. Table 4 shows goat nutrition survey. The majority (86%) of goats feed on pasture with supplements offered at the end of grazing. Other minority (14%) goats are fed in the backyard. Cakes feeding-frequency only values 3% of the herds. Water (of 46% purity) is sometimes available from pipes and/or the Nile. Some 54% of the owners mixin Dura flour as supplement. Table 4. Goat nutrition survey at Fitaih El Agaleein, 25km south of Khartoum. Domain Feed Feed offer Cakes feeding frequency Water Water quality Water availability Item Pasture+ supplement Backyard 1-2Kg/day >2Kg/day Unweighed Always Once daily Twice daily None Pipes Pipes and Nile Pure Contaminated Mixed with salt Mix with dura flour All the time Some times Number of Heads 67 11 0 0 80 0 0 2 69 60 18 36 0 0 42 0 80 % 86% 14 0 0 100% 0 0 3% 97% 77% 23% 46% 0 0 54% 0 100% Table 5 shows goat reproduction survey. Herds with males constituting 5-10% were 41%. Insemination occurs soley naturally, where males originating from within the herd were 55% .Other males (45%) come from the surrounding farms. 66 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Only 32% of the herd females were conceiving with 40% of the herd females having 2-4 conceptions and normal (93%) deliveries. Most goats (45%) conceive once per annum with 49% of the herd females giving single kids. Lactating goats were 69% of the herd with 67% of them spent 2-6 month on lactation. Table 5. Goat reproduction survey at Fitaih El Agaleein, 25km south of Khartoum. Domain Males Insemination Source of male Pregnancy Times pregnant Pregnancy frequency Twinning Delivery Births Lactation Period lactating Item < 5% 5-10% 0% (Females only) Artificial Natural Within herd Surrounding farms Conceiving Non conceiving 1-2 2-4 >4 Once per annum Once every 2 yrs.. Other Twins always Single always No pattern Normal Abnormal 1-2 2-4 >4 Lactating Dry One month 2-3 months 4-6 months >6 months 67 Number of heads 16 32 30 0 80 42 35 23 50 24 26 16 36 24 20 21 39 20 74 6 21 22 12 54 24 1 20 14 16 % 21% 41% 38% 0 100% 55% 45% 32% 68% 36% 40% 24% 45% 30% 25% 26% 49% 25% 93% 7% 38% 40% 22% 69% 31% 2% 39% 28% 31% Ahmed, Aisha B. M. , Ph.D Thesis, 2008 In goat health survey (Table 6), 90% of the herd looks normal in appearance. Foreign body appeared in 9% of the goats. On clinical examination parameters were normal (100%) or up to 76% normal. Internal parasites infestation detected were coccidia (mild 25% and moderate 17%), strongyloides (mild 8.5%) and moniezia (moderate 8.5%). Mixed infestations were seen with either strongyloides (17%) or moniezia (8.5%) with coccidia In about 87% of heads remedies were given as treatment but only at need. Table 6. Goat health survey at Fitaih El Agaleein, 25km south of Khartoum. Domain Remedies Remedy frequency Health appearance Gait Abdominal palpation Respiratory rate Pulse rate Temperature Hair coverage, length and color Item Prevention Treatment Additives Weekly Monthly At need Normal Abnormal Normal Abnomarl Foreign body Nothing Normal Abnormal Normal range 60-70 Normal range 70-80 Normal range 80-90 <95 Normal Abnormal Normal Allopecic Long Short Black Black + Other 68 Number of heads 10 68 0 0 0 80 72 8 80 0 7 73 80 0 15 25 28 8 80 0 79 1 39 8 74 6 % 13% 87% 0 0 0 100% 90% 10% 100% 0 9% 91% 100% 0 20% 33% 37% 10% 100% 0 99% 1% 83% 17% 93% 7% Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Table 6. Continued Skin Udder Buccal cavity Teeth Tounge Lacrimation Nasal discharge Vaginal discharge Pneumonia External parasites Internal parasites Feacal consistency Normal Abnormal Normal Abnormal Normal Abnormal Normal Abnormal Normal Abnormal Normal Abnormal Normal Abnormal Normal Abnormal Diagnosed Free None Average High Mild Coccidia Moderate Coccidian Mild Moniezia + Coccidia Moderate Moniezia Mild Strongyloides Mild Strongyloides + Coccidia Normal Abnormal 78 2 78 2 79 1 78 2 80 80 74 6 80 11 69 61 19 0 3 2 1 1 1 2 97% 3% 97% 3% 99% 1% 97% 3% 100% 100% 93% 7% 100% 13% 87% 76% 24% 0 25 17 8.5 8.5 8.5 17 80 0 100% 0 Table 7 shows haematological values for 12 heads, randomly selected out of the surveyed adult goats. The average values for white cells were within the normal range of reference values. Of the red blood cells values, HB, HCT and MCHC were within the normal limits. MCV and MCH values were very high and RBCs count was very low compared to literature values. 69 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Table 7. Goat herds haematological values at Fitaih El Agaleein, 25km south of Khartoum. Item White cells Parameter WBC (µl) LYM (µl) LYM % Bas.+Eosino.+ Mono./µl Bas.+ Eosino.+Mono.(%) Neutr. ((µl) Neutr. (%) RBC (µl) HGB (dl) HCT (%) MCV (fl) MCH (pg) MCHC (dl) Red blood Cells Number of heads 12 12 12 12 12 12 12 12 12 12 12 12 12 Mean ± s.d. 18.39 ± 4.52 10.23 ±3.77 55.85 ±12.89 3.10 ± 3.20 14.40 ±11.61 6.03 ±2.14 30.77 ± 3.75 2.80 ± 0.44 8.88 ± 1.08 29.61 ± 4.86 105.86 ± 8.18 32.14 ± 4.33 30.49 ± 4.66 Table 8 shows serum metabolites, enzymes and minerals values for 12 heads, randomly selected out of the surveyed adult goats. All parameters tested fell within the normal ranges cited in the literature, except for LDH which was found high. Table 8. Goat herds serum metabolites, enzymes and minerals values at Fitaih El Agaleein, 25 km south of Khartoum. Item Parameter Serum metabolites Glucose (mg/dl) Serum enzymes Urea (g/dl) Total Protein (g/dl) Albumin (g/dl) Globulin (g/dl) Total bilirubin (g/dl) Creatinine (mg/dl) AST(µl) CK (CPK) LDH Na (mg/dl) Ca (mg/dl) K (mg/dl) P(mg/dl) Serum minerals 70 Number of heads 12 Mean ± s.d. 52.92 ± 16.09 12 12 12 12 12 12 12 12 12 12 12 12 12 27.50 ±12.76 6.50 ± 0.65 3.57 ± 0.92 3.02 ± 0.92 0.20 ± 0.06 0.50 ± 0.12 133.14 ± 18.90 192.33 ± 143.19 834.08 ± 134.99 141.75 ± 1.96 9.63 ±0.75 4.37 ± 0.30 5.02± 2.40 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 3.2 Protein realimentation of adult debilitated Nubian goats 3.2.1 Performance Table 9 shows performance values of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks. Feed intake directly variated with the crude protein content in the diet. Feed intake was higher in group D (16% CP) than groups B and C 12% and 14% crude protein respectively. Daily body weight gain was higher for goats fed the highest crude protein (group D) than for those fed 12 and 14% CP in the diet in a linear response. The highest crude protein-fed group D had the lowest food conversion ratio comparable for the other two groups B and C. Table 9. Performance values of experimental adult goats fed at constant energy (9MJ ME / kg) and variabe crude protein for 11 weeks. Item A control B 12%CP C 14%CP D 16%CP Initial weight (Kg) 17.70 17.60 17.30 16.50 Final weight (Kg) 19.00 21.10 21.30 21.30 Total weight gain (Kg) 1.30 3.50 4.00 4.80 Daily weight gain (gm) 17.00 45.50 51.90 62.30 Total feed intake (Kg) 40.23 40.70 43.17 44.67 Daily feed intake (gm) 523.0 529.0 561.0 580.0 Daily energy intake (MJ) 3.10 4.76 5.05 5.22 FCR 31.00 11.60 10.80 09.30 Figures 1, 2, 3 and 4 show growth curves of experimental groups A, B, C and D. Regression coefficients were inferior to the control group (0.72). Group C coefficient (0.66) is superior to the other two groups B and D. 71 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 gr.1 Observed 19.50 Y = 0.72 x + 17.21 SE 0.138 Linear 19.00 Figure 1. Growth curve of the control group A fed at 6MJ ME / kg and crude protein 8% for 11 weeks. 18.50 18.00 17.50 17.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00 weeks gr.2 Observed 25.00 Y = 0.535 x + 16.73 SE 22.50 Figure 2. Growth curve of experimental group B fed at constant energy (9MJ ME / kg) and crude protein 12% for 11 weeks . Linear 0.637 20.00 17.50 15.00 12.50 10.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00 weeks gr.3 Observed Y = 0.656 x + 16.36 SE 0.486 Linear 22.00 Figure 3. Growth curve of experimental group C fed at constant energy (9MJ ME / kg) and crude protein 14% for 11 weeks. 20.00 18.00 Y = 0.559 x + 17.03 SE 0.645 16.00 14.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00 weeks gr.4 Observed 25.00 Y = 0.559 x + 17.03 SE 0.645 Figure 4. Growth curve of experimental group D fed at constant energy (9MJ ME / kg) and crude protein 16% for 11 weeks. Linear 22.50 20.00 Y = 0.559 x + 17.03 17.50 SE 0.645 15.00 12.50 10.00 0.00 2.00 4.00 6.00 weeks 72 8.00 10.00 12.00 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 3.2.2 Blood values Table 10 shows average values of red blood cells of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks. All of the red cells and their indices of the test groups were not affected (p>0.05) by the increase in CP in the diet. Table (10). Average (mean ± s.d.) values of red blood cells of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks. Treatment A (8% CP 6MJ) B (12% CP 9MJ) C (14% CP 9MJ) D 16% CP 9MJ) RBC 106 / mm3 HGB g/dl HCT % MCV mm3 MCH g/dl MCHC % 2.40± 0.53 8.99± 1.62 25.71± 7.31 105.68± 12.06 37.66± 2.26 36.26± 6.62 1.93± 0.77 NS 7.65± 2.35 NS 20.15± 8.65 NS 105.80± 13.45 NS 41.14± 7.02 NS 39.63± 6.42 NS 2.20 ± 0.44 NS 9.16 ± 0.87 NS 24.90± 6.32 NS 112.41± 8.70 NS 42.79± 7.63 NS 38.36± 7.61 NS 2.24± 0.40NS 8.61± 1.24 NS 24.41± 6.25 NS 107.99± 13.43 NS 38.62± 2.34 NS 36.31± 5.22 NS 3.2.3 White and differential white cell values Table 11 shows average values of white and differential white blood cells of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks. Values of total WBC, lymphocytes, grouped basophils, eosinophils and monocytes and neutrophils all in number and percentage were not affected (p> 0.05) by the increase of crude protein in the diet. 73 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Table (11). Average (mean ± s.d.) values of white and differential white blood cells of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks . Parameters Treatments A (8% CP 6MJ) B (12% CP 9MJ) C (14% CP 9MJ) D 16% CP 9MJ) Total WBC /µl 12.17± 2.57 13.49± 2.23 NS 13.24± 4.40 NS 11.88± 2.20 NS Lympho. Lymph. /µl % 5.20± 42.37± 2.24 16.49 8.83± 63.26± 2.65 NS 11.25 NS 7.92± 56.52± 3.44 NS 11.47 NS 6.07± 50.90 ± 1.41 NS 6.32 NS Bas.+ Eosino.+ Mono. /µl Bas.+ Eosino.+ Mono. % 2.60± 1.13 Neutr. /µl Neutr. % 18.35± 6.15 6.45± 0.78 50.85± 10.63 1.10 ± 0.60NS 8.90 ± 2.54NS 5.40 ± 1.46 NS 33.39± 9.55 NS 1.40± 0.68 NS 11.50± 6.58 NS 4.25± 1.68 NS 35.07± 7.69 NS 1.13± 0.59 NS 8.93± 2.45 NS 5.13± 1.36 NS 42.56 ± 6.23 NS 3.2.4 Serum values Table 12 shows average serum parameters of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks. Glucose, total protein, albumin, globulin and calcium were not affected (p>0.05) by the increase of crude protein in the diet, while phosphorus increased significantly (p< 0. 05) with increase of crude protein in the diet of all test groups. Creatinine increased (p> 0.05) with the increase of crude protein in the diet. The AST activity decreased (p> 0.05) with the increase of crude protein in the diet. 74 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Table (12). Average (mean ± s.d.) values of serum parameters of experimental adult goats fed at constant energy (9MJ ME / kg) and variable crude protein for 11 weeks . Group A C P 8%, 6 MJ B 12% Glucose mg% 42.00 ± 7.38 45.33± 5.63 NS TP g/dl 7.64± 0.67 6.48± 0.77 NS Parameters Alb Glob. g/dl g/dl 2.82± 4.80± 0.51 0.83 2.93± 3.54 ± 0.80NS 0.80 NS C 14% 43.78± 5.45 NS 6.93 ± 0.59 NS 2.80± 0.47 NS 4.13 ± 0.66 NS 0 46 ± 0.21 NS 0.49 ± 0.12 NS D 16% 43.33± 13.98 NS 7.37 ± 0.77 NS 3.22± 0.37 NS 4.03 ± 0.62 NS 0.48 ± 0.13 NS Creat mg/dl 0.44± 0.11 P mg/dl 2.98± 1.05 5.39 ± 1.24 5.47± 1.91 4.84 ± 1.28 Ca mg/dl 8.85± 0.69 8.76 ± 1.21 NS Ast U/L 276.38± 173.79 113.56 ± 42.97 NS 8.27 ± 0.77 NS 248.6 ± 176.79NS 8.74 ± 0.65 NS 133.5 ± 55.89 NS 3.3 Energy realimentation of adult debilitated Nubian goats 3.3.1 Performance Table 13 shows performance values of experimental adult goats fed at constant protein (12%) and variable energy for 11 weeks. Feed intake was lowest in group D (12MJ/Kg) and higher in group B (8MJ/Kg DM). Body weight gain was the same for goats fed 8 and 10MJ/Kg and was lowest in group D goats fed the highest energy (12MJ/ Kg). The goats fed lower energies (groups B and C) had food conversion ratios11.10 and 10.50 respectively, while that fed highest energy (group D) had the best feed conversion ratio (10.10). Table 13. Performance values of experimental adult goats fed at constant protein (12%) and variable energy for 11 weeks . Item Initial weight (Kg) Final weight (Kg) Total weight gain (Kg) Weight gain /day(gm) Total feed intake (Kg) Daily feed intake (gm) Daily energy intake FCR A control B 8 MJ C 10 MJ D 12MJ 17.70 19.00 1.30 17.00 40.23 523.0 3.10 31.00 15.30 19.00 3.70 48.10 41.20 535.1 4.28 11.10 17.70 21.40 3.70 48.10 38.90 505.2 5.05 10.50 18.90 22.00 3.10 40.30 31.50 409.1 4.91 10.10 75 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Figures 5, 6, 7 and 8 show growth curves of experimental groups A, B, C and D. Regression coefficients of groups B and D were inferior to the control group (0.72). Group C coefficient (0.87) is superior to the control group. gr.2 aY = 0.72 x + 17.21 22.50 SE 0.138 Observed bY = 0.35 x + 14.92 SE 0.856 Linear 20.00 17.50 15.00 12.50 10.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00 weeks Figure 6. Growth curve of experimental group B fed at constant crude protein 12% and energy 8 MJ ME / kg for 11 weeks . Figure 5. Growth curve of the control group A fed at 6MJ ME / kg and crude protein 8% for 11 weeks. dY = 0.44x + 17.89 SE 0.732 cY = 0.87 x + 17.32 SE 0.207 Figure 8. Growth curve of experimental group D fed at constant crude protein 12% and energy 12 MJ ME / kg for 11 weeks . Figure 7. Growth curve of experimental group C fed at constant crude protein 12% and energy 10 MJ ME / kg for 11 weeks . 76 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 3.3.2 Blood values Table 14 shows Average values of red blood cells of experimental adult goats fed at constant (12%) crude protein and variable energy for 11 weeks. The RBCs and their indices were not affected (p>0.05) by the increase ME in the diet. Table (14). Average (mean ± s.d.) values of red blood cells of experimental adult goats fed at constant (12%) crude protein and variable energy for 11 weeks. Groups A (Cp8%E6MJ) B (8MJ,12%CP) C (10MJ,12CP) D (12MJ, 12CP) RBC µL 2.40± 0.53 2.87± 0.22 NS 2.88± 0.40 NS 2.41± 0.90 NS HGB DL 8.99± 1.62 8.75± 0.90 NS 8.66± 1.34 NS 8.70± 1.41 NS Parameters HCT MCV % fL 25.71± 105.68± 7.31 12.06 30.59± 106.33± 4.59 NS 9.10 NS 28.80± 101.61± 3.57 NS 11.49 NS 27.61± 115.94± 9.95 NS 11.68 NS MCH Pg 37.66± 2.26 30.80± 4.78 NS 30.52± 4.97 NS 39.04± 9.38 NS MCHC DL 36.26± 6.62 29.29± 5.73 NS 30.47± 3.08 NS 33.62± 7.07 NS 3.3.3 White and differential white cell values Table (15) shows average values of white and differential white blood cells of experimental adult goats fed at constant 12% protein and variable energy for 11 weeks. WBC, lymphocytes, grouped basophils, eosinophils and monocytes were not affected (p>0.05) in number and percentage by the increase of ME in the diet. Lymphocytes % increased (p>0.05) in all test groups with the increase of ME in the diet, while neutrophils decreased significantly (p<0.05) in number and percentage in groups C and D. 3.3.4 Serum values Table 16 shows average serum parameters of experimental adult goats fed at constant (12%) protein and variable energy for 11 weeks. Glucose, albumin, creatinine, calcium and AST values were not affected (p> 0.05) by the increase of ME in the diet. Total protein and globulin were not affected (p> 0.05) by the increase of ME in the diet 77 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 except for values in group D which were significantly (p< 0.05) lower. Phosphorus showed a significant (p< 0.05) increased in all test groups. Table 15. Average (mean ± s.d.) values of white and differential white blood cells of experimental adult goats fed at constant 12% protein and variable energy for 11 weeks . Parameters Groups A (Cp8%E6MJ) B (8MJ,12%CP) C (10MJ,12CP) D (12MJ, 12CP) Bas.+ Eosino.+ Mono. /µl Bas.+ Eosino.+ Mono. % 42.37± 16.49 63.48± 11.75 NS 2.60± 1.13 1.60 ± 0.81 NS 18.35± 6.15 6.80 ± 5.56 NS 6.13± 1.78 NS 62.83± 6.81 NS 7.84± 5.07 NS 61.86± 13.48 NS 0.80 ± 0.77 NS 1.40± 0.82 NS 8.20 ± 4.3 NS 15.13± 9.99 NS Total WB /µl Lympho. /µl Lymph. % 12.17± 2.57 15.31± 6.23 NS 5.20± 2.24 9.33± 5.13 NS 11.05± 4.84 NS 11.90± 5.68 NS Neutr. /µl Neutr. % 6.45± 0.78 4.70 ± 0.95 NS 47.42± 14.30 32.29± 11.45 NS 3.00 ± 0.21* 31.47± 1.23* 3.43± 0.31* 29.58± 3.28* NS= Non significant. * Means in a column are significantly different (P<0.05). Table 16. Average (mean ± s.d.) serum parameters of experimental adult goats fed at constant (12%) protein and variable energy for 11 weeks . Parameters Group Glucose mg/dl A 42.00± (Cp8% 7.38 TP g/dl 7.64± 0.67 Alb g/dl 2.80± 0.48 Glob. g/dl ±4.82 0.83 Creat mg/dl 0.46± 0.12 P mg/dl 2.98± 1.05 Ca Mg/dl 8.85± 0.69 6.09± 2.23 4.30± 0.20 5.89± 2.12 8.47± 126.67± 1.23 NS 33.38 NS E6MJ) B (8MJ,12%CP) 45.38± 5.95 NS 7.11± 0.84 NS 3.05± 0.37 NS ±4.19 0.91 NS 0.54± 0.21 NS C (10MJ,12CP) 40.00± 6.03 NS 7.15± 0.67 NS 2.65± 1.18 NS 4.50± 0.87 NS 0.52± 0.13 NS D (12MJ, 12CP) 49.56± 7.38 NS 6.64± 0.81 3.03± 0.59 NS 3.61± 0.44 0.54± 0.14 NS 78 Ast µl 276.38± 173.79 7.83± 96.67± 1.27 NS 20.47 NS 8.39± 0.93 NS 105.67± 32.67NS Ahmed, Aisha B. M. , Ph.D Thesis, 2008 CHAPTER FOUR DISCUSSION The surveyed debilitated female Nubian goats are classified as milk goats (less than 30kg body weight) and were herded in mostly less than optimum herd sizes (10-20 heads). Some social (ownership) and geographic factors (grazing area) govern the herd size. Smaller sizes usually offer better management and attention of the herder - who is likely be the owner- but that turns to be costly in overheads. Usually adult stock (2-4 years) is herded. Feeding is on range with scarce fodder offers and mostly none of the cakes. Water source is pure, uncontaminated from domestic pipes, when most stock receives a supplement of dura flour mixed in. Tropical goat breeds are late maturing breeds (Kallah et al., 2000 and CollinsLusweti, 2000). Eventhough, these surveyed goats are subjected to under nutrition from early age, and were born themselves from debilitated parents. Their growth rates are slow and usually achieve puberty late. Their milk yield is low and gives off-springs after longer intervals. Shortage of energy is translated immediately into a drop in production in dairy animals. Over a longer period of time, other effects such as retarded growth, delayed puberty and decreased fertility will become apparent (Mary and David, 1994). Undernutrition is one of the major setbacks of animal production in the tropics (Kallah et al., 2000 and Collins-Lusweti, 2000). A seasonal weight loss of up to 40% in beef and mutton herds can be expected (Clariget et al., 1998) in extensive systems with lack of supplementation, as demonstrated by Jordan and Le Feuvre (1989). Energy insufficiency was known to affect growth and productivity of animals more than any single nutrient (Blaxter, 1956). Tilton and Warnik (1964) showed that both protein and energy deficiencies had caused severe bodyweight losses. 79 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 The erythrocytic series showed a number of adaptive changes to mal or undernutrition. The normal hematocrit value reflects normal blood fluidity, hence these goats were not considered dehydrated. The low number of RBCs at normal Hb values had created high MCH with an adaptive change to a very high MCV, rendering normal MCHC. High MCV is usually seen in regenerative anemias (William, 2001and Blood and Radostits, 1989). Though the white cells of the surveyed goats were within the normal range, yet exhibit a rise over the average number. Differential white cell values show lymphocytosis that may be in response to environmental challenges but animals were not stressed as judged by the normal number of neutrophils. Stress neutrophilia had been noted by Jain (1986) in domestic animals. The surveyed goats’ urea was found high but within normal limits. Goats, and likewise other ruminants, can perform well with low protein supply in marked adaptation to conditions of poor nutrient availability and lack of water. Increase in blood urea nitrogen (BUN) can occur in dehydration, by reducing the glomerular filtration of urea, also mild BUN increases may occur with a high-protein diet or subsequent to digestion of blood following gastro intestinal hemorrhage. Decrease in BUN may occur also with dietary protein restriction or hepatic insufficiency (William, 2001and Blood and Radostits, 1989). Desert breeds such as the Black Bedouin have a superior ability to conserve urea under adverse dietary conditions. In comparative studies with Swiss Saanen goats, both breeds could significantly increase the tubular reabsorption of urea when fed lowprotein diets, but the Bedouin goat possessed a superior capacity to reduce GFR, thus lowering the amount of urea filtered by the kidney (Silanikove, 1984). Urea thus conserved is available to the rumen microflora for protein anabolism. Mild increases in 80 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 BUN accompany the increases of protein catabolism as when animal is feverish or starved. Surveyed goats’ creatinine was considered low. Creatinine is found in the skeletal muscle; hence creatinine concentration is related to the muscle mass. Heavily muscled or well-conditioned animals may have serum creatinine at the highest end of the reference range. Conversely, creatinine concentration may be low in animals having marked loss of muscle mass (William, 2001and Blood and Radostits, 1989). Our surveyed goat appeared of normal total protein, albumin and globulin. Increases or hyper-proteinemia occur with dehydration. Non-anemic cases have concurrent elevations in total protein, globulin, and hematocrit values. Decreases or hypo-proteinaemia occur with external losses, decreased protein intake or increased protein catabolism (William, 2001and Blood and Radostits, 1989). Enzymes AST and LDH are not liver-specific and can also result from muscle cell damage or excessive exercise as with these astray goats. Diseases affecting hepatic parenchyma usually cause hepatocytic disruption and can lead to a measurable increase in serum levels of a number of intracellular hepatic enzymes in goats. Increased AST with normal to mild increase of ALT may indicate that the source of the AST was not only from the liver. In the case of muscle damage, there should be a simultaneous increase with CK (William, 2001and Blood and Radostits, 1989). Serum mineral profile of the surveyed goats show normal values reflecting an efficient kidney function in reabsorption as an adaptive mechanism to restricted environmental resources, but levels of sodium and phosphorus were at minimum normal scale. Most livestock in many parts of the world consume diets that do not meet their mineral requirements. In consequence nutritional disorders arise, which range from acute or severe mineral deficiency diseases, characterized by well-marked clinical signs, pathological changes and high mortality to mild and transient conditions, difficult to 81 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 diagnose with certainty and express merely unthriftiness or unsatisfactory growth, production and fertility (McDowell, 2003). It appears that all shrubs can be considered as Na non-accumulators because they contain less than 2 g Na kg−1 DM (Youssef, 1988). Moreover, during all seasons all plants had lower Na content to meet the needs of a growing adult range goat. A goat weighing about 50.0 kg BW consuming 2.0 kg day−1 DM of these shrubs could eat substantial amounts to meet their requirements of K in all seasons (Ramirez et al., 2006). Similar findings were reported by Greene et al. (1987), Ram´ırez et al. (2001), Moya-Rodr´ıguez et al. (2002), Cerrillo-Soto et al. (2004) and Ram´ırez-Ordu˜na et al. (2005) who evaluated K content in browse species growing in arid and semi-arid regions of the world. All plants, in all seasons, had phosphorus contents that were not sufficient to meet adult goat requirements (Ramirez et al., 2006). Ramirez et al. (2001), Moya- Rodr´ıguez et al. (2002) and Ram´ırez-Ordu˜na et al. (2005) also reported that shrub species were deficient in phosphorus in all seasons. Most plants had higher levels of the tested minerals during summer. Ca, Mg, K, Fe and Mn contents in all plants in all seasons can be sufficient for the requirements of grazing goats, while Na, P, Cu and Zn contents were marginally deficient in all seasons However, different plants differ in their minerals content significantly and depending on their floral density may cause needs for supplementation during certain seasons. Also, interference between mineral levels during certain seasons need to be considered. It appears that ration formulation for goats should include evaluation of the dominant available plants and consideration of their probable mineral contents during certain seasons for ration formulation (Ramirez et al., 2006). Herd owners do not go for disease prevention, but rely on treatment the moment diseases occur i.e. only at need. Clinically, most of these goats appear normal in pulse, 82 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 respiration, temperature, skin and hair coverage, udder, buccal cavity, teeth and tongue and faecal consistency. These goats suffer no lacrimation or vaginal discharges, but less than 10% of them suffer nasal discharges and foreign body. Parasitic load is average (coccidia, moniezia and strongyloides) in less than quarter of them and 11% of them were found pneumonic. On either protein or energy realimentation of debilitated goats, the control groups mostly resemble the surveyed goats being put on a maintenance diet but they showed a slight increase in body weight. This increase may be due to in-pens-keeping which reserves some energy used to be expended in the field. CSIRO (1990) indicated that with good grazing conditions, MEa is 10 -20 % greater than activity cost in pen or stall environments and can be 50% greater with extensive conditions in which land is hilly and walking distances are great. There are several reports available on the energy requirements of goats (NRC, 1981). Energy requirements in open range may increase several folds over those assumed for restrained animals (Lachica and Aguilera, 2005). Feed intake has increased with increasing CP level of the diet; feed intake was higher with the 16% CP than either 12% or 14% CP. Elliott and Topps (1993c) found that voluntary consumption of low protein diet by sheep increased significantly with increasing protein level of the deit. Lu and Potchoiba (1990) used growing goats and found that DM intake decreased curvilineary as dietary ME density increased. The DM intake increased linearly as dietary CP level increased. Mavrogenis et al. (1979) used goat kids of both sexes to study the effect of three dietary crude protein levels. They found that the daily dry matter consumption per kid was increased with increasing CP level of the diet. Ageeb (1992) reported higher daily gains during the first 3 months for both male and female kids of Baggara goats of South Kordofan, Sudan. He found the average daily gains at different stages of growth (3, 6, 9 and 12 months) diminishing with advancing 83 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 age. In the normal growth curve rates of gain tend to diminish with progress in age especially post-pubertally. This explains the slow growth of the adult goats in this experiment. They need longer time to gain minor weight because of age and long period of under-nutrition since weaning age, even suckling was not believed to be sufficient in quantity and time from debilitated under-fed dams. Hence FCR of the control goats was exceptionally high (31) on the maintemance low energy (6 MJ) and low protein ( 8%CP) in the diet.In the present study feed intake decreased with increasing ME level of the diet, this agrees with Owen and Gray (1992) that feed intake declines as energy concentration increases. Feeds that are dusty tend to cause irritation of the nose and eyes of animals and decrease feed intake. Ruminants increase their feed intake in response to an increase in demand for energy and protein or both (Kenedy and Milligan, 1987).The feed in the present study was somewhat dusty and it may have had affected feed intake and consequently decreased body weight gain. In this study the average daily gain was the same in groups B and C ( 8 and 10 MJ/ Kg DM respectively) and low in group D (12 MJ/Kg DM). Sanjuva et al. (1990) found a growth rate increase as the energy level increase irrespective of the protein levels. Ibrahim (1996) fed entire male Desert kids three levels of energy 12, 10, and 8 MJ/Kg DM and found that the diet with high and medium energy level had higher final weight compared with the low energy level diet. He also found that FCR was 7.6, 11.9 and 24.06 for the high, medium and low energy levels. Wilson and Obsourn (1960) and Tulloh (1963) stated that under nutrition in the earlier stages of growth is more detrimental to an animal than is restriction at a later stage. Consequently, the age at which an animal is subjected to under nutrition is important to determine the reversibility of the under nutrition status and the degree of the compensatory growth achieved on re-alimentation. Bohman (1955) noted that cattle under one year of age were slower on compensation after an energy insufficiency period 84 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 and they needed longer re-feeding periods than mature cattle subjected to similar treatments. Gaili (1975) observed no compensatory growth in lambs whose growth was restricted between birth to one month of age and 1-2 months of age on rehabilitation. The likelyhood of body weight increase in CP re-alimentation at increasing CP levels rather than with increasing energy re-alimentation may be due to the functional supplementation of tissue loss during under nutrition by the crude protein. Previously restricted animals must be fed ad libitum to high plane of nutrition to take advantage of their compensatory growth potential (Wilson and Osbourn, 1960; Ashworth and Millward, 1986; Mersmann et al., 1987; Summers et al., 1990 and Marais et al., 1991). Nutrient composition in diet is one of the factors influencing an animal’s ability to recover from the effects of undernutrition, among which the most attention has been paid to protein restriction (Wilson and Osbourn, 1960). There have been a number of investigations on farm animals showing that a complete recovery in body weight was obtained after a period of protein restriction. The overall loss in body weights remained approximately 5% in those subjected to restricted diet, followed by grazing/re-alimentation. Ledin (1983) reported that sheep on a 60% ad libitum diet had not fully recovered their live weight by 73 days after resuming ad libitum feed intake. Gomez et al. (1999) studied the effect of long term feed restriction on metabolism and tissue composition of adult goats. They found that plasma insulin did not differ between the treatments, but the final live weight, blood glucose, carcass and hepatic tissue protein deceased. The liver and muscle DNA increased significantly with restriction. The results suggested the capacity of goats to adapt to long term under nutrition and the importance of hepatic and muscle tissues as sources of metabolic energy. 85 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 The RBCs parameters were not affected by either increase in dietary energy or crude protein. RBCs indices showed a number of adaptive changes to mal-nutrition as seen in the control and surveyed goats. White and differential white cell values were not changed by both type realimentations, but there was lymphoctosis which may be an environmental effect. Both type alimentations show decreased neutrophils especially in goats fed 10MJ and 12MJ ME/Kg. That indicates the treated animals were not under stress compared to the control group. Stress neutrophilia had been noted by Jain (1986) in domestic animals. A neutrophil count greater than 7,200/ul represents neutrophilia and less than 1,200 /ul, is neutropenia (Mary and David, 1994). Values of glucose, albumin and calcium were not affected by either energy or protein supplementation. With protein supplementation the total protein and globulin were not affected. Ruminants usually do not depend as monogastric animals on glucose as the main energy source and exhibits minor fluctuation. Higher energy supplementation affected the energy protein ratio and posed more demend for protein with the higher supply of energy. Protein fraction globulin seemed to follow total protein. Creatinine increased nonsignificantly in all energy and protein supplemented groups. Creatinine is found in the skeletal muscle; hence creatinine concentration is related to the muscle mass. Heavily muscled or well-conditioned animals may have serum creatinine at the highest end of the reference range. Conversely, creatinine concentration may be low in animals having marked muscle loss (William, 2001and Blood and Radostits, 1989). Energy or protein supplementation successfully achieved weight gains sufficient to increase the creatinine level. Enzyme AST decreased nonsignificantly in all test goats realimented for either energy or protein. This indicates that either shortage met by supplementation contributes to improvement of the muscular damage and a better gain and metabolic cure. 86 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Phosphorus increased significantly in all test groups of both realimentations. Increased intake with formula feed increased P intake. All grazing plants across all seasons had insufficient phosphorus content to meet adult goat requirements (Ramirez et al., 2006). Ramirez et al. (2001), Moya- Rodr´ıguez et al. (2002) and Ram´ırezOrdu˜na et al. (2005) also reported that shrub browse species were also deficient in phosphorus when tested in all seasons. Most plants had higher levels of minerals Ca, Mg, K, Fe and Mn during summer, and their content across all seasons can be sufficient for the requirements grazing goats, whereas Na, P, Cu and Zn content were marginally deficient across all seasons. The regulation of P serum level depletes body stores and phosphorus deficiency may be masked because serum concentration remain within the normal range Most livestock in many parts of the world consume diets that do not meet their exact mineral requirements. In consequence nutritional disorders arise, which range from acute or severe mineral deficiency or toxicity diseases, characterized by wellmarked clinical signs, pathological changes and high mortality to mild and transient conditions, difficult to diagnose with certainty and express merely an unthriftiness or unsatisfactory growth, production and fertility (McDowell, 2003). Mild deficiencies or toxicities assume great importance in the nutrition of livestock because of their inapparency. They can be confused with the effects of semi-starvation due to underfeeding, protein deficiency and various types of parasitic infection. In many parts of the world, animal productivity is limited primarily by shortages of available energy and protein, infections and parasitic disease and genetic inadequacies in the animal. As those limitations are increasingly rectified, local minerals deficiencies and imbalances are likely to become more apparent and more critical (Underwood and Suttle, 1999) The incidence and severity of mineral malnutrition can be further influenced, both directly and individually, by climatic factors, such as sunlight and rainfall. Sunlight 87 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 promotes vitamin D formation in the goat which in turn facilitates Ca and P absorption. The P concentrations in shrubs fall with increasing maturity and with the shedding of seeds. In any area, the relative lengths of the dry, mature period (low browse P) and of the green, growing period (high browse P) are determined by the incidence of rainfall (Minson, 1990). Conclusion The debilitated goats were found to be healthy, judged by the normal blood and serum parameters, despite debilitation and were adapted to poor nutrition and mild parasitism. Either protein or energy realimentation brings no significant or poor improvement on performance in the post-pubertal stage reflecting their malnutrition pre-pubertaly. Field goats receive restricted nutrients from graze which will not meet their energy, protein or mineral requirements, unless supplemented by the owner. Practical implications It is imperative to direct farm resources to feed the young growing stock at times of feed scarcity rather than feeding large stock. Adult goats can always show adaptive capabilities but it would be safee to keep them a little above maintenance. Debilitated astray goats should receive energy, protein and mineral (especially phosphorus) supplementations (balanced diet) to keep their body reserves at a reasonable level and secure their health status good. 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M. , Ph.D Thesis, 2008 APPENDIX I University of Khartoum Faculty of Animal Production Department of Animal Nutrition Goat Survey Form address………………………. Date…………………… 1. Goat herds Fitaih El Agaleein, 25km south of Khartoum Herd size (from which the sample was selected) < 10 Ecotypes Nubian Age : 1-2 Yrs Sex: Male Body weight 20 -30 kg Production purpose Milk Herd manager Owner Site Farm 10 -20 20 -50 Local crosses Foreign crosses 2-4 yrs > 4yrs > 50 Female 30 -50 kg Meat Dual Other Other with pay Indoors Non specific Range 2. Goat nutrition Fitaih El Agaleein, 25km south of Khartoum Feed Pasture + Supplement Feed offer 1-2Kg/day Cakes feeding frequency Always Backyard > 2 Kg/day un-weighed Once daily Twice daily 111 Non Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Water Pipes Water quality: Pure Water availability All the time Pipe and Nile Contaminated Mixed with salt Mixed + dura Some times 3. Goat reproduction survey Fitaih El Agaleein, 25km south of Khartoum Male: Female < 5% 5- 10 % Insemination Artificial Natural Source of male Within herd Surrounding farms Pregnancy Conceiving Non Conceiving Times pregnant 1-2 2-4 Pregnancy frequency Once / annum Once every two years Twinning Twins always Single always Delivery Normal Abnormal Birth 1-2 2-4 Lactation Lactating Dry Period Lactating One month 2-3 months % (Female only) >4 Others Not pattern >4 4-6 months >6 months 4. Goat health survey Fitaih El Agaleein, 25km south of Khartoum Remedies Prevention Remedy frequency Weekly Health appearance Normal Gait Normal Treatment additives Monthly At need Abnormal Abnormal 112 Ahmed, Aisha B. M. , Ph.D Thesis, 2008 Abdominal palpation Foreign body Respiratory rate Normal Pulse rate Nothing Abnormal Normal range 60-70 Normal range 80-90 Temperature Normal Abnormal Hair coverage, length and color Normal Alopecic Long Short Skin Black Black + Other Normal Abnormal Udder Normal Abnormal Buccal cavity Normal Abnormal Teeth Normal Abnormal Tounge Normal Abnormal Lacrimation Normal Abnormal Nasal discharge Normal Abnormal Vaginal discharge: Normal Abnormal Pneumonia Diagnosed Free External parasite Non Average Internal parasite Mild coccidia Moderate coccidia Moderate moniezia Mild strongyloides + coccidia Feacal consistency: Normal Abnormal Normal range 70-80 < 95 High Mild + coccidia Mild strongyloides N.B : Information acquired in this form will only be used for research purposes. 113