Carcass composition and meat quality of muscovy ducks in

Carcass composition and meat quality of muscovy ducks in

TuRr et al., Carcass composition and meat quality of muscovy
RAUEN , H. W„ 1985 : A uswirkungen des Gens für Befiederungsreduktion und Nackthalsigkeit (Na-Gen) auf das
produktive Adaptationsvermögen von Legehennen an
hohe U mgebungstemperaturen. Diss . agr. TU Berlin
r. 152.
257
SELMI , E„ 1983 : Wechselwirkungen zwischen Legereife und
Legepersistenz beim Legehuhn unter E influß vo n Umwelttemperatur und Körpergewicht. Di ss. agr. TU Berlin.
Ko rrespondenzadresse: Prof. Dr. P. Horst, Inst. f. Grund lagen der Nutzticrwisscn sc haflen, Lcnrzeallce 75, D - 141 95 Berlin
Arch. Geflügelk. 1994, 58 (6), 257 - 261, ISSN 0003-9098. © Verlag Eugen Ulmer G mbH & Co„ Stuttgart
Carcass composition and meat quality of muscovy ducks
in response to clenbuterol administration 1
Zusammensetzung des Schlachtkörpers und Fleischqualität bei der Moschusente nach Verabreichung von
Clenbuterol
Rosa Maria Turi*, P. Sacch i**, 1. Romboli ***
Manuskript eingegangen am 15. Oktober 1993
lntroduction
Many substances have been investigated in order to find
the means of improv ing animal productions .
In recent yea rs, ß-adrenergic agonists have received particular attention as they have been proved effective in
promoting growth rate and reducing fat deposition (HA RAHAN et al. , 1986).
The efficiency of these substances varies considerably in
relation to species, sex and age of the animals, to the
ß-agonist employed, to the dose and the duration of the
treatment. In fact, the mode of action of ß-adrenergic
substances and the intensity of the effect are modulated by
the different metabolic pathway involved.
Birds seem to be less responsive to these additives even
tho ug h in broiler chickens the ß-agonist clenbuterol has
been reported to increase growth rate, improve feed efficiency and reduce carcass fat (DALRYMPLE et al„ 1984; HANRAHAM et al„ 1986; T AKAHAS HI et al„ 1993). The employed
level of clenbuterol in chickens is comprised, in the majority
of cases, between 0.125 and 5 ppm. evertheless, the type
of res ponse is not always proportionally related to the dose.
Because of the great variability of the effects in avian
species and the lack o f information about the ß-agonists in
birds other than chickens, we have carried o ut an investigation on the administration of clenbuterol to muscovy ducks.
1
The research was supported by a gram of ltalian
ational
Research Council (C.N. R.)
* Diparcimenco di Patologia Animale, Universita T orino, Icalia
** Dipartimenco di Produ zioni Animali , Ep idemiologia ed Ecolog ia, Uni vers ira T orin o, ltalia
*** Dipartimenco di Scienze Anatomiche, Fisiologlche e delle
Produz ioni Animali, Universira Pisa, ltalia
Archiv fü r Geflüge lk unde 6/ 1994
In a first trial, the effect of 0.2 ppm clenbuterol was studied
in fem ales (ROMBOLI et al„ 1992). In the present paper, we
report the results of a second trial, carried o ut in order to
stud y the effect of higher levels of clenbuterol administration
to male duck s o n grow th rate, carcass composition and meat
quality.
Table 1. Ing rediencs and chemical compos iti on of basal diet
Inhaltsstoffe 1111d chemische Z11sammensetz1111g der Grundrationen
lngredients :
Maize
Soyabean meal (50 % CP)
Meat and hone meal (50 % CP)
Luzerne meal
Gluten meal (63% CP)
Mixed vegeca l oi ls
Calcium carbonate
Sodiu m chloride
Vit. and min . premix*
%
60
20
8
5
4.5
1
0.700
0.300
0.500
Calcul ated compositi on
Moisture (%)
E nergy (Mj /kg)
Crude protein (%)
Ether extract (%)
Crude fiber (%)
Ash (%)
Calcium (g/ kg)
Available phosphorus (g/kg)
L-Lys in (g/kg)
D -L Methionine (g/kg)
Cystine (g/kg)
*
13.0
13.48
20.0
4.6
5.7
8.0
8.8
4.5
10.4
3.7
3.2
Premi x/kg: vit. A 13200 UI, vit. D3 3300 Ul, vit. E 20 mg, vit. PP 50 mg, vit. B2
5.5 mg, vit. ß1 2 0.0 18 mg, vit. K 2.5 mg, Co 0.5 mg, Fe 60 mg, Mn 60 mg, Cu 4 mg,
Cholinc 1000 mg, Zn 40 rng, I 1 mg, 0 -L Mcthionine 1700 mg, D -pa nthotcnic acid 20 mg,
Z inc Bacytracin 20 mg, Erhossichi ne 125 mg.
258
TuRt et al., Carcass composition and meat quality of muscovy
Table 2. Measurements and anal ysis performed during the trial
D ie 1Vährend des Versuches durchgeführten M essungen und A 11a!Jse11
1. A ni111als perfo r111ances
initial and final live weight
weight gain during the experimental period
feed con version ratio
2. Sla11ghtering traits
eviscerated weight (plucked, bleeded and excluding gut)
carca ss weight (plucked, bleeded and excluding head, neck,
fat, trachea, oesophagus, liver, heart, gizzard and gut)
weight of:
breast muscle
heart
liver
gi zzard
abdominal and peri visceral fat
skin and subcutaneous fat
head, neck and feet
3. M eat characteristics
pH at 24 h
breast muscle color (colorymetric measure of "L", "a" and
" b" indexes)
breast muscle composition:
moisture, crude protein, fat and ash (AOAC methods)
total collagen (ISO method)
heat solubility of collagen (HrLL, 1966)
Table 3. Body weight during the trial
E11t1vick/1111g des Körperge1vichtes IVahrend des VersJ1ches
Treatment
da ys
Age (d)
0
21
14
mean sd
rnean sd
mean sd
56
63
70
2337
2690
3120
3305
3487
2390
2789
3101
3449
3569
2330
2601
3093
3372
3600
77
84
35 .1
34.9
34.2
36.2
38.6
34.2
36 .0
42.1
38.4
41.1
35.1
41.4
33.5
37.9
45.1
1) Cro1vth rate
The final live weight of ducks given clenbuterol is higher
than that of control subjects, but no statistically significant
difference has been detected (table 3).
For what growth rate is concerned (table 4), the effect of
clenbuterol is evident only in the group which received the
ß-agonist when the animals were o lder, even though the
total period of administration resulted shorter.
The feed conversion ratios are decreased by the treatment,
but not in a significant way.
2) Slaughtering traits
At slaughtering time, the subjects which resulted the heaviest
and the lightest from each pen, were discarded and 15 birds
out of each group were randomly taken for the dissection
and for the analysis. This practice reduced the internal
variability in the groups; as a consequence, it was possible
to put in evidence the statistically significant favourable
effect of clenbuterol on the final live weight at the moment
of the slaughtering (table5).
The weight of carcasses in the experimenta l gro ups was
nearly 150 g higher than in the control group. This increase
can be attributed almost completely to the growth of breast
muscles (table 6) which are, as it is weil known, the most
appreciated cut of the carcass in avian species.
An unexpected resu lt has been observed in gizzard, which
appears less heavy in subjects receiving clenbuterol for
21 days. Fora plausible explanation, one should refer to the
pharmacological ro le of the ß-agonist.
The amount of abdomina l and perivisceral fat is decreased
in treated birds, but the differences are statistically not
significant. These resu lts are in agreement with the conclusions of the study of DALRYMPLE et al. (1983), who studied
clenbuterol effects in broilers. On the contrary, in a previous
Table 4. Weight gains (W.G. ) and feed conversion ratio (F.C.)
from the 63th to 84th day of age
C e1vichtsz11nah111e 1111d F11ttervmvert11ng bei den Moschusenten vom 63. bis
zum 84. L ebmstag
Materials and Mi!thods
A total of 195 male Muscocy ducklings were randomly
assigned to 3 g roups, each with 5 replications, and housed
in 15 pens.
A basal diet, whose composition is reported in table 1,
was used. The experimental diets were supplemented with
2 ppm of clenbuterol and given to one group for 21 days
(from 63th to 84th day of age) and to a second group fo r
14 da ys (from the 70th to the 84th day of age). At the
85th da y of age, 15 birds randomly collected from each pen
were slaughtered and the carcasses dressed following the
indications of WPSA (1984).
All the measurements and analysis performed in this trial
are summarized in table 2.
The data collected were subjected to analysis of variance;
the significance of differences among treatments was determined using Scheffe' s multiple range test.
R esults and discussion
The results of the trials are reporred in tables 3, 4, 5, 6, 7
and 8.
Treatment
days
W.G.
F.C
0
21
14
mean sd
mean sd
mean sd
791A
7.2
749A
6.9
1006 8 50.8
5.9
0.93
30.1
0.52
36.1
0.71
Mcans with different supcrsc ript w ith in a ro w arc sig nificandy di ffe rent (P < 0.01)
Table 5. Body wei ght and carcass yields at slaughtering
Körperge/llichte 1111d L eistungen bei der 5 chlachtt111g der Moschusenten
Treatment
days
21
14
mean sd
mean sd
3544A 33.4
2636 58.6
3655A 8 40.5
2708 36.8
3708 8 42.7
2751 34.6
2162A 17.9
2297 8 36.8
2316 8 31.7
0
mean
Body wei ght g
E viscera ted
weight* g
Carcass** g
sd
*
plu ckcd, blecded and cxcl uding gu t
pluc kcd , bl ceded and cxcl udi ng hcad, neck , fcct, trac hca, o esophagus, li vc r, hcart,
gizza rd , gut
Mcans with different superc rip t within a row are signi ficantl y different (P < 0.01)
**
tl rchi v für G cOügclkundc 6/ 1994
TuRr et al., Carcass composition and meat quality of muscovy
Tab le 6. Slaughte ring traits
Z erlegebefunde der Schlachttierkörper
Treatment
days
0
mean
Breast muscle g
Heart g
Liver g
Gizzard g
Abdominal and
perivisceral fat g
Head , neck
and feet g
Skin and
subcutaneu s fat g
Gut g
21
sd
mean
14
sd
mean
sd
13.9
0.44
1.70
1.75
6.40
423A 10.9
23.3
0.74
69.7
2.78
88.lb 2.99
52.9
7.03
535 8 15.8
23.7
0.77
69.1
2.21
77.2" 2.84
41.4
4.17
497 8
24.7
67.4
78.7"b
47.7
417.5
417.0
437 .1
307.2
7.23
13 .6
159
4.67
261.7
168
6.00
12.4
9.64
281.0
158
6.41
13.4
6.26
1\!lca ns wirh d ifferent su pc rscript within a row arc sig nifi cantly different (a, b: P < 0.05;
A, ß , P < 0.01)
trial (ROMBOLI et al., 1992), we found that fat pad was
unexpectedly increased by clenbuterol administered to female ducks.
The skin and subcutaneous fat weight as weil are decreased
by the treatment.
On the whole, the decrease in fat tissue of the carcass of
muscovy ducks seems to be directl y associated with the
length of the administration.
In fact, birds fed the ß-agonist for 21 days showed a more
marked reduction of the fat deposition.
259
In the case o f the ß-agonists treat ment, panel tests cannot
be accomplished as the safety of these substances has not yet
definitely proved. So, the determination of collagen content
as weil as physical tests (e.g. shear force measurement) seem
tobe, so far, the only way to evaluate their possible influence
on the eating quality of meat.
Our in vestiga tion showed a collagen decrease following the clenbuterol treatment, so confirming the stud y of
DA wsoN et al. (1990) on three muscles of steers treated with
cimaterol and that of BERGE et al. (1993) on other three
muscles of vea l ca lves administered clenbuterol.
On the other band, in spite of this collagen decrease, it
has been reported a lower meat tenderness meas ured as
mechanical resistence in treated animals (D AWSON et al. ,
1990; FIEMS et al., 1990) and o ur stud y puts in evidence a
reduction in the proportion of heat soluble collagen, which
is regarded as an important factor of meat tenderness. The
reduction of collagen solubility observed in o ur study is
statistically significant in muscles of the birds receiving a
21 da y trea tmen t.
The apparent contraddictio n between total collagen decrease accompanied by a decrease of its solubility following
the ß-agonists administration has been attributed to a less
intense postmortem proteolysi s with consequent reduced
m yofibrillar breakage or, in alternative, to a g reater degradation of nearl y formed collagen in comparison with the more
mature collagen whose numero us cross-links are definitel y
less heat soluble (D AwSON et al. , 1990).
lt must be no ted, howeve r, that a great part o f the studies
on these aspects of ß-agonist action have been carried out
3) Breast 11111scle col!lposition
Data reported in table 8 show a marked effect of clenbuterol
administration on protein, fat and collagen content, while
moisture and ash resulted unaffected by the treatment.
Protein increase is independent of the duration of the
administration. On the contrary, only a 21 day treatment
can significantly reduce fat content.
These resu lts are not consistent with those of our previous
investigation (ROMBOLI et al. 1992), in which no statistically
significant difference was found.
lt should be noted, nevertheless, that the two trials are
not completely comparable because they were different both
in <lose of the substance administered and in sex of the
animals.
ln ducks, clenbuterol seems to give a better responsiveness
in males than in females as regards protein and fat composition of breast muscle, while in chickens (DALRYMPLE et al.
1984) only females give significant responses.
lt has been suggested that ß-agonist inhibit the rate of
protein degradation , but are not able to increase the protein
synthesis in muscle (MoRGAN et al., 1989; MuRAMATSU et al„
1991). In this mode of action, an interference of species and
sex can be supposed.
As far as collagen content is concerned, a significant
decrease is induced by clenbuterol , irrespective of the length
of its administration.
Collagen, the main protein of connective tissue, is rega rded as one of the many factors which determine meat
tenderness. Some studies have demonstrated a significant
correlation between total amount of collagen and sensory
evaluation of meat quality (SMITH et al., 170), while other
investigations have denied such a correlation (CROSS et al.,
1973; CRousE et al., 1985).
Archi\· fü r Geflügelkunde 6f1994
Table 7. Breast muscle ph and color
Enllvickltmg des pi-! IVertes und der Farbe bei der Bmst11111sk ulatur
Treatment
days
pH
Color : L *
a**
b***
*
21
0
14
mean
sd
mean
sd
1nean
sd
5.7
37.2A
22.5
4.7
0.12
0.50
0.30
0.18
5.7
38.8A8
22.2
5.0
0.17
1.00
0.32
0.28
5.7
39.9 8
22.5
5.3
0.16
0.46
0.39
0.28
lightness
** rcd ncss indcx
**"'
ycllowness indcx
Mcans wi th different supc rscript wit hin a row arc signi ficantl y d ifferent ( P < 0.01)
Table 8. Breast muscle compos ition (% fresh matter basis)
Zusamnm1setz1111g der B nist11111skel11 (%iges Anteil über das frisches
Fleisch)
Treatment
da ys
Moisture
Crude protein
Fat
Ash
Collagen
Collagen
solubility %
0
21
14
mean
sd
mean
sd
mean
sd
76. 14
20.20A
0.94 8
1.16
2.52 8
8.07 b
0.62
0.44
0.26
0.10
0.22
0.90
75 .67
21.12 8
0.66A
1.22
1.73A
6.78"
0.58
0.61
0.16
0.09
0.30
0.69
75 .83
20.84 8
0.80All
1.21
1.60A
7.35a b
0.42
0.51
0.16
0.10
0.26
0.41
Means with diffe rent su pcrsc rip1 w ithin a row arc significantly different (A, ß : p
< 0.05)
"· b' p
< 0.01;
260 ·
TuR1 et al., Carcass composition and meat quality of muscov y
on bovine meat; in fact, in avian species, meat tenderness
is not a critical character.
For meat pH, no difference between control and treated
ani mals has been detected. Of the colour parameters, only
" L" value shows a significant va ri at ion, while the "a" and
"b" values (red and yellow indexes) seem unaffected. Since
" L" values are significantly increased only by the shorter
treatment (14 days) , it is difficult to suggests a correct
explanation about the exact role of clenbuterol in this aspect.
T o sum up, it is possible ro assert that a <lose of 2 mg/ kg
of clenbuterol is sufficient ro give some positive responses
in male mu scovy ducks.
For some parameters the response is independent of
the leng th of the treatment.
For the weight gain, the age is an important determinant.
In fact, when the ß-agonist is administered ro older birds,
ir gives a better response irrespective of the duration of the
administration period.
The most imporrant positive effects of clenbuterol in
muscovy ducks are: a) the reduction of abdominal and
perivisceral fat pad and b) the increase of breast muscle
weight. This increase is mainly due ro an higher amount of
protein in breast, since water and fat percentages are
un affected o r even diminished. So, also in muscovy ducks,
clenbuterol appears an efficient reparritioning agent.
The total collagen amount is decreased by the treatment,
however also decreases collagen solubility, which is a better
marker of the final tenderness of meat.
ln conclusion, the use of clenbuterol in male muscovy
ducks offers undeniable advantages in order to improve
man y aspects o f animals performances and carcass and meat
quality.
Obviously, further investigations are necessary to clarify
the rossicological role of this subsrance and /or its metabolites.
Slllll!ll ary
The effect of the ß-agonist clenbuterol has been studied in
male muscov y ducks evaluating their growing performances
as weil as characteristics of the carcass and quality of breast
muscles.
The <lose of clenbuterol added ro the basal diet was of
2 ppm and the treatment had a different length : one of the
two experimental groups received clenbuterol for 21 days
(fro m the 64th ro the 84th day of age) for the second group
the treatment had the duration of 14 da ys (from the 70th to
the 84th da y of age).
All the subjects was slaughtered at the age of 84 da ys and
carcass dissected following the indication of WPSA.
Clenbuterol did not affect the feed convertion ratio, but
the mean final weight and the weig ht gain were higher in
the subjects treated for 14 days.
The breast muscle weight was increased by clenbuterol
irrespectively of the duration of the treatment, while the
g izzard weig ht was decreased.
The analysis of breast muscle put in evidence a significant
increase of protei.n amount and a decrease of lipidic content.
Total collage n was reduced, but in the same time clenbuterol
reduced soluble collagen, which is a parameter that better
mar ks meat tenderness .
This confirms the observations of orher Authors who
assert that meat treated with ß-agonists is less tender.
pH at 24 h from slaughtering was not influenced by
clenbuterol nor was meat colour; only the "L" value, which
expresses lu minosity, resulted hig her in meat of subjects
treated with clenbuterol for 14 days.
Z11sat11mensetz11ng des Schlachtkörpers 11nd Fleischq11alität bei der
Mosch11sente nach Verabreich11ng von Clenb11terol
R. M. Turi, P. Sacchi, I. Romboli
Z11satlltllenjass1mg
Ziel dieser Arbeit war es, die Wirkung einer ClenbuterolVerabreichung auf Gewichtszunahme, Zusammensetzung
der Schlachtkörper und qualitiative Merkmale des Fleisches
bei den Moschusenten zu untersuchen.
2 mg pro kg Futtermischung wurden zwei verschiedenen
Gruppen von männlichen Entenküken peroral verabreicht.
Die Tiere der ersten Gruppe wurden vom 63. bis zum
84. Lebenstag (das heißt für 21 Tage) mit Clenbuterol
behandelt. Für die Tiere der zweiten Gruppe, dagegen
dauerte diese Verabreichung nur 14 Tage (von 70 . bis zum
84. Lebenstag).
Die Enten wurden geschlachtet, als sie 85 Tage alt waren,
und ihre Schlachtkörper wurden anhand der Angaben der
WPSA zerlegt. Die Behandlung mit dem ß-Agonisten übte
keinen besonderen Einfluß, weder auf die WachstumGeschwindigkeit noch auf die Futterverwertung aus. Nach
einer kürzeren (14 Tage) Verabreichung von Clenbuterol
wurden im allgemeinen höhere Körpergewichte gemessen .
Bei allen behandelten Tieren zeigte die Brustmuskulatur
eine signifikante Gewichtszunahme, unabhängig von der
Dauer der Behandlung , während das Gewicht des Muskelmagens deutlich abnahm.
Für die Brustmuskeln ließen sich eine deutliche Erhöhung
ihres Proteingehaltes und eine Verminderung des Fettgehaltes ermitteln.
Auf Grund der Behandlung nahm der Kollagengehalt der
Muskeln deutlich ab, aber zugleich wurde auch eine Verminderung seiner Löslichkeit beobachtet.
D as stimmt mit den Ergebnissen anderer Verfasser überein, wonach sich das Fleisch der mit Clenbuterol behandelten
Tiere als ziemlich zäh erweist. Die 24 Stunden nach der
Schlachtung der Moschusenten durchgeführten Messungen
des pH-Wertes und der Farbe von Brustmuskeln ließen keine
besondere Veränderungen erkennen. Nur die Messung der
Farbhelligkeit des Fleisches ergab höhere Werte bei den
Tieren, die 14 T age lang mit Clenbuterol behandelt worden
waren.
Stich11Jorte
Moschusente, Fütterung, Additiva, Leistung, Fleischqualität.
L iterat11re
AOAC, 1985: Official Methods of analysis (14. th Ed.)
Association of Official Analytical Chemists. Washington,
D.C.
BERGE, P., ]. CuLIOLI, A. QuALI, M. F. PARAT, 1993: Performance, muscle composition and meat texture in veal
calves administered a beta-agonist (Clenbuterol). Meat
Sei., 33, 191 - 206.
British Standards Institution, 1979: Methods of test for Meat
and Meat products. Part 11. BS4401.
CROSS H. R. , Z. L. CARPENTER, G. C. SMITH, 1973 : Effects
of intramuscolar collagen and elastin upon bov ine muscle
tenderness. J. Food Sei., 38, 998- 1001.
CRousE, ]. D., H. R. CROSS, S. C. SE!DEMAN, 1985: Effects
of sex condition, genotype, diet and carcass electrical
Archiv für Geflügel kunde 6/ 1994
KALETA
et al. : Möglichkeiten zur Schätzung des Alters von Hühnerkük en
stimulation o n the collagen content and palatability of
two bovine mu scles. J. Anim. Sei. , 60, 1228- 1234.
D ALRYMPLE R. H., P. K. BAK ER , P. E. GrNGHER, D. L. lNGLE, J. M. PENSACK, C. A. RrcKs, 1984: A ripartitioning
agen t to improve performance and carcass composition
of broilers . Po ultry Sei ., 63, 2376- 2383.
DAWSON J. M ., P. J. BuTTERY, M . GrLL, D. E. BEEVER,
1990: Muscle composition of steers treated with the
Beta-agonist Cimaterol. Meat Sei., 28, 289 - 297.
FrnMs L. 0 ., B. BuTS, C. V. BouCQUE, D. I. D EMEYER, B. G .
CoTTYN, 1990: E ffect of a beta-agonist on meat quality
an d myofibrillar protein fragmentation in bulls. Meat Sei. ,
27, 29 - 39.
H AN RAHAN J . P. (Ed .), 1987: Beta-ago nists and their effects
on animal g rowth and carcass qu ality. Elsevier Applied
Science Publishers, London .
Hr LL F., 1966: The solubility o f intramuscular collagen in
meat animals of various sizes. J. Food Sei ., 31, 161 - 166.
MoRGAN J. B., S. J. J ONES, C. R. CALKINS, 1989: Muscle
protein turnover and tenderness in broiler chickens fed
cimaterol. J. Anim. Sei., 67, 2646- 2654.
MuRAMATSU T., M. KAKITA, Y. AOYAGI, ]. ÜKUMURA,
1991: Research no te: Beta-Adrenergic Agonist effects o n
li ver and breast muscle protein synthesis in female chick s.
Poultry Sei. , 70, 1630- 1632.
Arch. Geflügelk. 1994, 58 (6), 261- 267, ISS
I
261
RoMBOLI I., R. M. TuRr, P. SACCHI, C. SARRA, 1992 : Prove
preliminari sull'impiego di un beta-agonista nell'alimentazione dell 'anatra muschiata. Proceeding National
Congress " Parliamo de carni avicole e cunicole", pag. 243.
SMITH G. C., Z. L. CARPENTER, 1970 : Lamb carcass qu ality.
3. Chemical, ph ysical and histological meas urements. J.
Anim . Sei., 31, 697- 702.
TAKAHASHI K., Y. AKIBA, M. HORIGUCHI, 1993: Effects of
a beta-adrenergic agoni st (Clenbuterol) on perfo rmance,
carcass composition, hepatic microsomial mixed function
oxidase and antibody production in female broilers treated
with o r without corticosteron. Br. Poultry Sei., 34,
167- 175.
\,'\IPSA, 1984: Methods of dissection of broiler carcass and
description of parts. (JENSEN J. F. ed .) Perga mon Press,
Cambridge, U.K.
Anschrift des Au to ren : Rosa Maria Turi , Facoalta d ie Mcdicina Vcrerina ria , Via Nizza
52 1 101 26 Torino, Jtalia
0003-9098. © Verlag Eugen Ulmer GmbH & Co., Stuttgart
Möglichkeiten zur Schätzung des Alters von Hühnerküken innerhalb der
ersten Lebenswoche
Attempts to estimate the age of chicks within the first week of life
E. F. Kaleta , B. Sch ildger, F. Ende rs, S. He rzberge r und M. Roschinsky
Manuskript eingegangen am 10.
ovember 1993
Einleitung
Hühnerküken schlüpfen mit einem zur Gesamtgröße der
Tiere relativ großen Dottersack. Der Dotter dient den
Küken innerhalb der ersten Lebenstage als alleinige ahrungsquelle; ein zusätzliches Füttern und Tränken der Tiere
ist in dieser Zeit nicht erforderlich . Deshalb besagt die
„ Verordnung zum Schutz von Tieren bei der Beförderung in
B ehältnissen" vom 20. Dezember 1988 (BGB!. Teil I Nr. 60,
S. 2431) im §4 (Pflichten des Absenders), A bsatz 5: „Einragsküken, die innerhalb von 72 Stunden nach dem Schlupf
den E mpfänger erreichen, ... brauchen während der Beförderung nicht gefüttert und getränkt zu werden. "In diesem
A us dem In sti tut für Geflügelkrankheiten der
Univeristät Gießen
A rchiv für Geflü gelkunde 6/1994
Justus-Liebig-
Sinne formuliert es auch die EG-Richtlinie 91 /628 E WG
sowie nachfolgenden Richlinien zum Schutz von Tieren
beim Transpo rt. Auch die „Dritte Verordnung zur A.ndermtg
der Verordn11ng z11m Sch11tz gegen die Geflügelpest und die
Newcastle-Krankheit" (En twurf derzeit) definiert in § 1,
Punkt 8 „Eintagsküken als Geflügel in einem A lter vo n
weniger als 72 Stunden, das noch nicht gefüttert wurde".
In der auffindbaren und zugä ng lichen älteren (DRUMMOND 1916/17; LATIMER, 1924) und neueren Fachliteratur
finden sich wo hl morpho logische Angaben zur groben
Schätzung des A lters junger Küken (LucAs und STETTENHEIM, 1972; LOEFFLER, 1978 ; KRÖNER, 1983; ScHLOTYSSEK,
1987). Es fehlen jedoch ge nauere morph o logische Angaben ,
die eine A ussage darü ber ermög lichen , ob ein Hühnerküken
älter oder jünger als 72 Stunden ist. Die A ufnahme des
72-Stundenwertes in die EG-Richtlinien und beiden oben