Deel 2

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BRAHM AN
June
2012
2012
Junie
BRAHM AN
22
Tackling delayed puberty
in Brahmans
Research shows genes associated with late-onset puberty in heifers are
also the same as those associated with late-onset puberty in bulls. This
means that selecting either bulls or heifers for earlier puberty will also
reduce age at puberty in their half-sibs
There are major differences in cattle reproductive rates in northern and
southern Australia, in part because the hardy Bos indicus breeds that dominate
beef production in the tropics reproduce more slowly than the temperate Bos
taurus breeds, particularly when they are suckling a calf.
In the harsh tropical environments where these breeds evolved, this was a
desirable survival mechanism to ensure survival of the breed. However under
current production systems in northern Australia, where management practices
such as weaning of calves and supplementary feeding can be implemented,
the poorer reproductive rates now represent a major inefficiency for the beef
industry.
Beef CRC and CSIRO PhD researcher Marina Fortes says the major beef breed
in Australia’s north, the Brahman, is much better adapted than the taurine
breeds to high temperatures and humidity, parasites such as ticks, worms and
buffalo flies and seasonally poor pasture quality during the dry seasons.
Under these conditions Brahman bull calves typically do not reach puberty
before 18 to 24 months of age, much later than the taurine breeds. Tropical
composite breeds like Belmont Red, Charbray, Santa Gertrudis, Brahman
crossbreds and Senepol, comprising various admixtures of indicus and taurine
genes and grazed at pasture in the tropics also reach puberty later than British
bulls reared in temperate environments.
Ms Fortes studied veterinary science as an undergraduate at the University of
Sao Paulo in Brazil, and came to Australia in 2008 with husband Laercio Porto
Neto, who had won a PhD scholarship to work with Dr Bill Barendse at the
Beef CRC.
Initially she worked for a year as a research assistant in the Animal Genetics
Laboratory (AGL) at the University of Queensland, before successfully applying
to also undertake PhD studies with the Beef CRC, supported by Meat and
Livestock Australia.
Marina says reducing the age of puberty in Bos indicus and crossbred bulls to
less than 12 months has potential to improve productivity, reduce production
costs, and, by shortening the generation interval, accelerate rates of genetic
gain for other desirable traits. But achieving rapid gains requires a radically
new breeding strategy, based on highprecision genomics.
“As part of my PhD project, I used data from two herds of cows bred by the Beef
CRC, one comprising of 843 Brahmans and the other 866 Tropical Composite
cows,” Marina said. “CRC researchers from the Animal Genetics and Breeding
Unit (AGBU) had previously found there was a large variation in the age of
June
Her research has confirmed that some of the genes associated with lateonset puberty in heifers are also the same as those associated with late-onset
puberty in bulls. This means that selecting either bulls or heifers for earlier
puberty will also reduce age at puberty in their half-sibs.
BRAHM AN
Ms Fortes is passionate about her research, because of its potential to boost
the productivity of the beef industry in northern Australia, and in other tropical
areas throughout the world.
2012
Delayed puberty in Brahman and Tropical Composite breeds, in combination
with the harsh production conditions, means most Brahman cows do not
produce their first calves until they are at least three years old.
23
puberty, particularly in Brahman heifers, indicating strong potential for
genetic improvement.”
They had also found that age at puberty was highly heritable and
related to other traits such as weight gain and body composition traits.
In addition to this field data, the CRC used the Illumina 50K SNP chip
to genotype each animal.
More recently, Beef CRC researchers used the Illumina 800K SNP chip
to screen selected Brahman and Tropical Composite cows, as well as
some bull calves born to the Brahman cows. Ms Fortes then crossmatched their SNP data with 22 measured traits recorded as part of
the AGBU analyses to identify candidate genes for early puberty.
She found several SNP markers on chromosome 14 that were
associated with the concentration of growth-promoting Insulin-like
Growth Factor-1 (IGF1) in blood samples of both the experimental
bulls and heifers.
Cattle chromosome 14 turned out to be highly prospective: it carried
several candidate genes for early puberty, known rather cryptically as
PLAG1, XKR4, MOS and PENK.
PLAG1 is a transcription factor gene – a master regulator gene – that
may control serum levels of IGF1. The PENK gene codes for an opioid
receptor in the brain, known to be associated with fertility, while mice
lacking a functional MOS gene are infertile.
Ms Fortes says the genes cluster within a 2-megabase (2 million
DNA “letters”) region of chromosome 14, where the SNPs used for
genotyping are too sparse to indicate which of the genes is the key
player in early puberty. So the researchers are re-analysing the region
with the high-resolution 800K SNP chip to see if they can pinpoint the
exact gene causing the differences between animals in age at puberty.
BRAHM AN
Junie
2012
The X chromosome is another hotspot for earlypuberty genes,
especially genes that influence sperm quality and scrotum
circumference, another predictor of early puberty. “It’s funny to think
that the female chromosome is associated with male reproductive
traits, but this is what we found,” Ms Fortes said.
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Each key gene will contain at least one unique variation (a marker) in
its DNA sequence that distinguishes it from all other variants of the
same gene: i.e. the mutation that originally caused the functional
change contributing to early puberty. A gene-testing kit to detect
these markers will allow breeders to screen their breeding line for
animals carrying the gene variants once they are identified.
Ms Fortes says the impact on herd reproduction rates from these
advances in genomics will not be immediate. But beef producers in
northern Australia will benefit as superior herd bulls selected for early
puberty and high fertility progressively increase the calf output in their
herds.
- Beef CRC, Bulletin, Q1 2012.
USING THE 800K CHIP
Genomics, the study of the organisation and
function of a species’ full DNA sequence,
allows molecular geneticists to pinpoint
the very source of the differences between
individuals of the same species, or breed.
Most genetic variation between individuals
of the same species, or breed, traces to
tiny differences in DNA sequence which
subtly alter the function of the protein
encoded by a gene, or change the way the
gene functions. Most of these variations
involve single nucleotide polymorphisms
(SNPs – pronounced “snips”): singleletter substitutions that accumulate over
evolutionary timescales through mutation.
Genomics technology company Illumina’s
BovineSNP50 chip carries an array of 50,000
short DNA sequences from the spectrum of
known SNPs from individual cattle. Beef CRC
researchers have used it to screen the DNA
of more than 10,000 animals in a technique
called a genome-wide association study, or
GWAS.
Whenever a DNA sequence on the chip
detects a matching sequence in the DNA of
one of the cows or bulls in the sample herd,
the tiny patch of the chip carrying that SNP
changes colour, confirming the cow has
inherited that particular variation in the DNA
sequence.
The chip reveals which variants or “alleles” of
the DNA sequence every animal has inherited
in 50,000 spots (SNPs). This reflects the extent
to which the animals have inherited the same
gene variants.
Checking shared SNP alleles against
measurements of the full range of different
carcase and meat quality, feed efficiency and
reproduction traits in the test herds reveals
associations between a particular trait, and
particular SNPs that occur at high frequency
in animals exhibiting the desirable aspect of
the trait.
The location of every SNP on the chip is
known accurately, from a chromosomal map
of the cattle genome. When several SNP
alleles from the same region of a particular
chromosome consistently appear in animals
that for example, reach puberty early but not
in animals with delayed puberty, geneticists
know an anonymous gene involved in early
puberty lies nearby.
The closer the SNP to the desirable gene
variant, the more likely they are to be
inherited together. Rarely, a SNP marker will
actually lie within the gene of interest, so its
presence guarantees the animal carries the
“gold standard” allele of the gene. It is readymade for inclusion in a commercial genetesting kit to rapidly identify animals with the
potential to produce early-breeding progeny.
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June
2012
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BRAHM AN
Junie
2012
Rooiwater/Redwater
in Suid-Afrika/South Africa
Rooiwater is ’n protosoïese bosluisoordraagbare siekte
van beeste wat van die grootste verliese by veeboere in
Suid-Afrika veroorsaak. Twee tipes Rooiwater kom in SuidAfrika voor, naamlik Afrika Rooiwater (Babesia bigemina) en
Asiatiese of Europese Rooiwater (Babesia bovis). Asiatiese
Rooiwater word slegs deur die Asiatiese bloubosluis,
Rhipicephalus microplus, oorgedra, terwyl Afrika Rooiwater
deur die Afrika bloubosluis, Rhipicephalus decoloratus,
sowel as die Asiatiese bloubosluis oorgedra kan word. Die
rooipootbosluis, Rhipicephalus evertsi, kan ook ’n rol in die
oordraging van Afrika Rooiwater speel, maar die rol wat dié
bosluise speel is baie laer as in die geval van bloubosluise.
Die bosluise word vektore van die siekte genoem.
Redwater is a protozoal tick-borne disease in cattle
that causes major economic losses to stock farmers
in South Africa. Two types of redwater occur in South
Africa: African redwater (Babesia bigemina) and Asiatic
or European redwater (Babesia bovis). Asiatic redwater
is only transmitted by the Asiatic blue tick, Rhipicephalus
microplus, while African redwater can be transmitted by
both the African blue tick, Rhipicephalus decoloratus, and
the Asiatic blue tick. The red-legged tick, Rhipicephalus
evertsi, can also be instrumental in the transmission of
African redwater, but the contribution of these ticks is far
less significant than that of blue ticks. The ticks are called
vectors of the disease.
Die verspreiding van beide Afrika en Asiatiese Rooiwater
in Suid-Afrika word geassosieer met die verspreiding van
die onderskeie vektore. Gunstige toestande vir beide
bloubosluisspesies is tradisioneel warm, vogtige toestande,
maar die bosluise het deur die land versprei deurdat boere
diere aangekoop het wat met bosluise besmet was. Die
bosluise het dan ook aangepas om te oorleef in hierde “niegunstige” toestande.
The dissemination of both African and Asiatic redwater
in South Africa is associated with the distribution of the
different vectors. Favourable conditions for both blue tick
species is traditionally warm, humid climatic conditions,
but the purchasing of tick-infested animals by farmers
caused the ticks to be spread right across the country. The
ticks had hence adapted to survive in these “unfavourable”
June
Introduction
BRAHM AN
Inleiding
2012
Dr Tom Strydom, MSD Animal Health
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Nuutste navorsing het getoon dat Afrika Rooiwater oor die
grooste deel van Suid-Afrika voorkom en net die droër dele
van die land, soos die Noord-Kaap en die Groot Karoo is vry
van die siekte. Asiatiese Rooiwater daarenteen kom voor
oor die grootste deel van die Limpopo Provinsie, Gauteng,
Mpumalanga, Kwazulu-Natal en teen die Oos-Kaapse kus
tot by ongeveer Swellendam in die Wes-Kaap.
Beide Afrika en Asiatiese bloubosluise is eengasheerbosluise, m.a.w. die lewensiklus van die bosluis vandat die
larfies op die bees klim totdat die wyfies volgesuig is, word
op een gasheer voltooi.
Simptome van Rooiwater
Rooiwater in beeste word gekenmerk deur depressie,
verlies aan eetlus, ’n hoë koors (>40.5 ºC), bloedarmoede
en tipiese rooi-swart uriene, vandaar die naam Rooiwater.
Geelsug kan in sommige diere gesien word.
In die geval van Asiatiese Rooiwater word dieselfde
simptome as met Afrika Rooiwater gesien, maar in die
meeste gevalle met die siekte gaan die dier in skok weens
die aansameling van parasiete in sy perifere bloedvate
wat lei tot ’n suurstoftekort in sy organe, orgaanversaking
en akute dood. In sekere gevalle van Asiatiese Rooiwater
word ook Serebrale Rooiwater gesien. In die geval samel
die parasiete in die bloedvate van die brein van die dier aan
en veroorsaak senuweesimptome in die dier. Die prognose
(sukses van behandeling) van Serebrale Rooiwater is baie
swak en diere wat die simptome toon moet dus van kant
gemaak word.
Asiatiese Rooiwater is dus in die meeste gevalle ’n per-akute
siekte en beeste wat met die siekte besmet word vrek ten
spyte van behandeling wat toegepas word. Die vermoede
is daarom dat die grootste verliese van Rooiwater in SuidAfrika weens Asiatiese Rooiwater is.
Die voorkoms van Rooiwater in beeste word deur ’n veearts
bevestig deur ’n bloedsmeer van die siek of dooie dier te
maak en dit onder ’n mikroskoop te ondersoek.
BRAHM AN
Junie
2012
Epidemiologie van Rooiwater in die bosluise
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In die geval van Afrika Rooiwater word die vektore met
die siekte besmet wanneer larfies op ’n besmette of
draerdier voed. Die siekte word dan van die larfies deur
die nimf stadium van die lewensiklus aan die volwasse
bosluise oorgedra. Besmette wyfies wat van die dier afval
dra dan weer die siekte deur die eierstadium (eiers word
op die grond gelê) na die volgende geslag van larfies oor.
Ons noem dit trans-ovariale oordraging. Die nimfe en
volwassenes van die volgende nageslag dra dan die siekte
oor aan vatbare diere.
Met Asiatiese Rooiwater is die verloop byna dieselfde
deurdat besmette wyfies die siekte trans-ovariaal aan haar
nageslag oordra, maar in die geval dra slegs die larfstadium
van die bosluis die siekte aan beeste oor. Die larfies verloor
die siekte na oordraging, maar die daaropvolgende nimfe
word weer met die siekte besmet, wat weer die siekte aan
die volwasse bosluise oordra.
Immuniteit en weerstand in die dier
Beide Rooiwaters het waarskynlik hulle ontstaan in die
tropiese dele van die wêreld gehad en alhoewel alle
beesrasse vatbaar is vir die siektes, is Sanga- en Zebu-rasse
conditions. Most recent research showed that African
redwater occurs over the largest part of South Africa, and
only the drier parts of the country, like the Northern Cape
and Great Karoo are free from this disease. Asiatic redwater,
on the contrary, prevails in the largest part of the Limpopo
Province, Gauteng, Mpumalanga, Kwazulu-Natal and along
the Eastern Cape coast to the proximity of Swellendam in
the Western Cape.
Both African and Asiatic ticks are single host ticks, in other
words the life cycle of the tick from such time as the larvae
climb onto the animal until the female ticks have become
saturated with blood, is completed on the same host.
Symptoms of Redwater
Redwater in cattle is characterized by depression, loss
of appetite, a high temperature (>40.5 ºC), anaemia and
typical red-black urine; hence the name redwater. Jaundice
can be observed in some animals.
Asiatic redwater and Africa redwater exhibit the same
symptoms, but most animals infected with the former
disease go into shock, due to the accumulation of parasites
in the periferal blood vessels, which leads to lack of oxygen
in the organs, organ failure and acute death. In certain cases
of Asiatic redwater, Cerebral redwater is also prevalent. In
this instance the parasites accumulate in the blood vessels
of the brain and cause neurological symptoms in the animal.
The prognosis (success of treatment) of Cerebral redwater
is not good at all and animals that display these symptoms
should be put down.
In most cases Asiatic redwater is therefore a peracute disease
and cattle that are infested with it, die, in spite of treatment
that is applied. This leads to the presumption that most of
the losses in South Africa due to redwater are to be ascribed
to Asiatic redwater. The incidence of redwater in cattle is
confirmed by a veterinarian after microscopic examination
of a blood smear taken from the diseased or dead animal.
Epidemiology of Redwater in ticks
In the case of African redwater the vectors are infected
with the disease when larvae feed on an infected animal.
The disease is then transmitted from the larvae through the
nymph stage of the life cycle to the mature ticks. Infected
females that fall from the animal then transmit the disease
through the eggs (eggs are laid on the ground) to the
next generation of larvae. This is known as trans-ovarian
transmission. The nymphs and mature ticks of the next
generation then transmit the disease to susceptible animals.
In Asiatic redwater, the course is more or less the same in
that infected females transmit the disease trans-ovarially to
her progeny, but here the disease is transmitted to cattle in
the larval stage of the tick. The larvae shed the disease after
transmission, but subsequent nymphs are again infected
with the disease and they, in turn, transmit the disease to
the mature ticks.
Immunity and resistance in the animal
Both redwaters probably had their origin in the tropical
regions of the world, and though all cattle breeds are
susceptible to the diseases, Sanga and Zebu breeds are
more resistant to the diseases than European breeds.
European breeds that thave not previously been exposed
to the diseases are especially highly susceptible to both
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June
2012
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Junie
2012
Kalwers van koeie wat voorheen aan ’n spesifieke Rooiwater
blootgestel was en wat immuun is teen die Rooiwater
is immuun teen die siekte van geboorte tot ongeveer 8
maande ouderdom. Die eerste 2 maande van die kalf se
immuniteit in die geval word van die biesmelk van die ma af
gekry en word passiewe immuniteit genoem.
Die immuniteit van kalwers is egter nie absoluut nie. Kalwers
waarvan die immuunstelsel nie optimaal is nie, bv diere wat
siektes soos BVD onder lede het, wat ondervoed is of hoë
parasietladings (interne sowel as eksterne parasiete) het,
kan vatbaar vir Rooiwater wees.
So kan selfs ouer diere wat voorheen aan die siekte
blootgestel was en immuniteit teen die siekte ontwikkel
het, vatbaar vir die siekte raak tydens “stress” toestande.
Beheer van Rooiwater
Die ideaal om Rooiwater in ’n kudde te beheer is om na
’n situasie van endemiese of enzootiese stabiliteit op die
plaas te streef. Per definisie is endemiese stabiliteit vir
Rooiwater die teenwoordigheid van beide vektore, Afrika
sowel as Asiaties bloubosluise, en beide Rooiwaters, Afrika
en Asiatiese Rooiwater, met minimale siekte op die plaas en
in die kudde.
Om immuniteit teen Rooiwater in die kudde te verseker
moet diere van ’n jong ouderdom af, tussen die ouderdom
van 3 tot 8 maande, aan die siekte blootgestel word. Daarom
is dit van uiterste belang dat die boer moet weet watter een
van Asiatiese of Afrika Rooiwater op sy plaas teenwoordig
is. Die besmettingsyfer van bloubosluispopulasies op
plase met Rooiwater is baie laag. In die geval van Asiatiese
Rooiwater kan dit so laag as 0.04% wees en in die geval
van Afrika Rooiwater 0.26%. Dus word hoë getalle van die
verskillende bosluisspesies op die kalwers benodig om te
verseker dat hulle deur ’n natuurlike besmetting op ’n jong
ouderdom aan die siekte blootgestel word.
Oor die algemeen word aanvaar dat die situasie met Afrika
Rooiwater in Suid-Afrika, waar die siekte voorkom, redelik
stabiel is. Weens die lae besmettingsyfer van Asiatiese
bloubosluise met Asiatiese Rooiwater (ongeveer 6 maal laer
as in die geval van Afrika Rooiwater) word dit egter aanvaar
dat die situasie met die siekte onstabiel is en dat endemiese
stabiliteit, deur op natuurlike besmettings staat te maak,
nie haalbaar is nie.
Bosluisbeheer
Beide Rooiwaters kan beheer word deur diere vry van
bosluise, veral bloubosluise, te hou. Weeklikse dip van diere
Calves of cows that have no immunity to redwater are
susceptible to the disease from birth to age two months.
From the age of two months the calves have a non-specific
natural immunity that lasts until approximately eight
months of age.
Calves of cows that have previously been exposed to a
specific redwater and are immune to redwater, are immune
from birth until approximately eight months of age. In this
case the calf’s immunity during the first two months comes
from the mother’s colostrum and is known as passive
immunity.
The immunity of calves is, however, not absolute. Calves
of which the immunity is not optimal, e.g. animals that are
sickening for diseases like BVD, that are underfed, or have
high parasitical infestation (internal as well as external
parasites), can be susceptible to redwater.
In this way even older animals that were previously exposed
to the illness and have developed immunity against it, can
become susceptible to the illness in stressful conditions.
Control of Redwater
The ideal to control redwater in a herd is to strive towards
a situation of endemic or enzootic stability on the farm.
Endemic stability for redwater is per definition the presence
of both vectors – African as well as Asiatic blue ticks, and
both redwaters – African and Asiatic, with minimal diseases
on the farm and in the herd.
To maintain immunity to redwater in the herd, animals
must be exposed to the disease from an early age: between
the age of 3 to 8 months. It is therefore critical for the
farmer to know which of the redwaters – Asiatic or African
– is present on his farm. The infection figure of blue tick
populations with redwater is very low. In the case of Asiatic
redwater it can be as low as 0.04% and in the case of African
redwater 0.26%. Large numbers of the different tick species
are therefore needed on the calves to ensure they will be
exposed to the disease at an early age by natural infection.
It is generally accepted that the situation regarding African
redwater, where it occurs in South Africa, is reasonably
stable. Due to the low infection rate of Asiatic blue ticks
with Asiatic redwater (approximately 6 times lower than in
the case of African redwater) it is, however, accepted that
the situation regarding the disease is unstable, and that
endemic stability, dependent on natural infections, is not
feasible.
Tick control
Both redwaters can be controlled by keeping animals
free from ticks, especially blue ticks. Weekly dipping of
animals in water soluble dipping agents should therefore be
executed. This procedure is, however, not recommended
and farmers that apply this procedure must make certain
that the dipping agent that is used on the farm is effective
to control the ticks. Blue tick resistance to dipping agents
2012
Kalwers van koeie wat geen immuniteit teen Rooiwater het
nie is vatbaar vir die siekte vanaf geboorte tot 2 maande
ouderdom. Vanaf 2 maande ouderdom het die kalf dan ’n
nie spesifieke natuurlike immuniteit teen die siekte wat tot
ongeveer 8 maande ouderdom duur.
Animals that have recovered from African redwater have
a certain degree of immunity to Asiatic redwater, but the
reverse is not true.
June
Diere wat herstel het van Afrika Rooiwater het wel ’n
mate van immuniteit teen Asiatiese Rooiwater maar die
omgekeerde is nie waar nie.
redwaters. In most animals a long-lasting immunity is
developed that can even last for life after a single exposure
to the diseases.
BRAHM AN
meer weerstandbiedend teen die siektes as Europese rasse.
Europese rasse wat nie voorheen aan die siektes blootgestel
was nie is veral hoog vatbaar vir beide Rooiwaters. In die
meeste diere ontwikkel ’n langdurige immuniteit wat selfs
lewenslank kan wees na ’n enkele blootstelling aan die
siektes.
31
met wateroplosbare dipmiddels moet dus toegepas word.
Die prosedure word egter nie aanbeveel nie en boere wat
die prosedure toepas moet seker maak dat die dipmiddel
wat op die plaas gebruik is effektief is om die bosluise te
beheer. Bloubosluisweerstand teen dipmiddels het oor die
afgelope 15 jaar in Suid-Afrika dramaties toegeneem en op
sommige plase kan die bosluise nie meer suksesvol deur
dompeldip of handbespuiting beheer word nie. Deur diere
skoon van bosluise te hou word die kudde volledig vatbaar
vir Rooiwater en wanneer die diere dan aan die siekte
blootgestel word kan die boer groot verliese lei.
Ons moet onthou dat enige middel wat vir die beheer van
bloubosluise geregistreer is Rooiwater kan beheer, maar die
middels sal nie die siekte voorkom nie. So bv sal Asiatiese
Rooiwater nie voorkom word deur beeste met middels wat ’n
sistemiese werking soos bv die makrosikliese laktoongroep
van middels (bv Ivotan G2858 (Act 36/1947)) of ‘n bosluis
groei-inhibeerder bv Acatak Pour-On G2422(Act36/1947))
te behandel nie. Om bosluise met die middels te beheer
moet die larfies eers bloed suig en dit neem gewoonlik 4
tot 5 dae voordat bosluise deur die middels geaffekteer
word. Aangesien larfies van die Asiatiese bloubosluis
verantwoordelik is vir die oordraging van Asiatiese
Rooiwater, sal die siekte reeds aan die diere oorgedra wees
voordat die larfies met die middels geaffekteer is.
Immunisering van diere
a) Inenting van kalwers
BRAHM AN
Junie
2012
Die enigste manier om te verseker dat kalwers wel op 3 tot
8 maande ouderdom aan die siekte blootgestel word, is om
die kalwers met die lewendige entstof van Onderstepoort
te ent. Entstowwe teen beide Rooiwaters is beskikbaar en
word direk van Onderstepoort Biologiese Produkte bestel.
In Suid-Afrika word diere egter deesdae net teen Asiatiese
Rooiwater ingeënt en daarom gaan die hantering van die
entstof hier bespreek word.
32
Die entstof word op droë ys versend en net genoeg entstof
wat op een dag gehanteer kan word moet bestel word,
tensy ’n bron van droë ys beskikbaar is om die entstof wat
nie gebruik word nie, bevrore te hou. Die entstof kan nie
in ’n huishoudelike vrieskas gestoor word nie, aangesien
die temperatuur daarvan nie koud genoeg is vir die stoor
daarvan nie.
Die entstof word teen ’n dosis van 1 ml per dier binnespiers
toegedien. Kalwers jonger as 2 maande moet nie geënt
word nie, aangesien passiewe immuniteit wat van die ma
verkry word, die effektiwiteit van immuniteit van die entstof
kan beïnvloed.
b) Inenting van diere ouer as 8 maande
Diere ouer as 8 maande het geen immuniteit teen enige
Rooiwater as hulle nie voorheen daaraan blootgestel was
nie. Daarom moet ouer diere wat met die entstof geënt
word gemonitor word vir die siekte na inenting. Die eerste
koorsreaksie na inenting teen Afrika Rooiwater word
gewoonlik 7 dae na inenting en met Asiatiese Rooiwater 10
tot 14 dae na inenting gesien.
Diere wat ’n koorsreaksie toon moet onmiddellik met
’n middel wat diminazene soos bv. Berenil RTU (G2702
Act36/1947) of imidocarb soos bv Imizol (G0831 Act36/1947)
behandel word. Diere moet nie met enige van die 2 middels
has dramatically increased in South Africa over the past 15
years, and on some farms the ticks cannot be controlled
successfully by immersion dipping or spraying any more. By
keeping animals free from ticks, the herd becomes totally
susceptible to redwater and when the animals are then
exposed to the disease, the farmer can suffer major losses.
We must remember that any remedy that has been
registered for the control of blue ticks can control redwater,
but it will not prevent the disease. Asiatic redwater will for
instance not be prevented by treating cattle with agents that
have a systemic action, like the macrocyclical lactone group
[e.g. Ivotan G2858 (Act 36/1947)) or a tick growth-inhibitor,
e.g. Acatak Pour-On G2422(Act36/1947)]. To control ticks
with these agents, the larvae first have to suck blood and
it usually takes 4 to 5 days before ticks are affected by this
agent. Since larvae of the Asiatic blue tick are responsible
for the transmission of Asiatic redwater, the disease will
already have been transmitted to the animals before the
larvae were affected with the agents.
Immunisation of animals
a) Vaccination of calves
The only way to ensure that calves are exposed to the
disease at age 3 to 8 months, is to vaccinate the calves with
the live vaccine from Onderstepoort. Vaccines against both
redwaters are available and can be ordered directly from
Onderstepoort Biological Products. In South Africa animals
are these days only vaccinated against Asiatic redwater and
for that reason administering of the relative vaccine will be
discussed here.
The vaccine is dispatched on dry ice and only the amount of
vaccine that can be managed on one day should be ordered,
unless a source of dry ice is available to keep the vaccine
that has not been used in a frozen state. The vaccine cannot
be stored in a domestic freezer, since its temperature is not
low enough for effective storage.
The vaccine is administered intramuscularly at a dose of
1 ml per animal. Calves younger than 2 months are not
vaccinated, since passive immunity obtained from the
mother can influence the effectivity of immunity of the
vaccine.
b) Vaccination of animals older than 8 months
Animals older than 8 months have no immunity to any
redwater if they have not previously been exposed to it.
Older animals that have been treated by this vaccine must
therefore be monitored for the disease after vaccination.
The first fever reaction after vaccination against African
redwater is usually observed 7 days after vaccination and
with Asiatic redwater 10 to 14 days after vaccination.
Animals that exhibit a fever reaction should immediately
be treated with an agent that contains diminazene, like e.g.
Berenil RTU (G2702 Act36/1947), or imidocarb, like Imizol
(G0831 Act36/1947) for instance. Animals should not be
treated with any of these two agents unless there are fever
reactions. Should this have occurred, both diminazene and
imidokarb will neutralize the effectivity of the vaccine and by
this prevent the animals from being immunized. Vaccination
against Asiatic redwater must be followed by temperature
readings from day 5 until day 21. It takes animals about 6
weeks to develop immunity to the disease after vaccination.
34
BRAHM AN
Junie
2012
Middels wat effektief is om Rooiwater te behandel, is middels
wat diminazene soos bv. Berenil RTU (G2702 Act36/1947)
en imidokarb soos bv Imizol (G0831 Act36/1947) bevat.
Die sukses van behandeling word egter bepaal hoe vroeg
in die verloop van die siekte die diere behandel word. Die
prognose van die siekte in diere met gevorderde Rooiwater
raak swakker en intensiewe behandeling deur die veearts
mag nodig wees om die diere te red. Selfs met intensiewe
behandeling kan die prognose steeds laag wees. In die geval
van ’n uitbreek van Rooiwater in ’n vatbare kudde moet
die hele kudde met Imizol (G0831 Act36/1947) of Berenil
RTU (G2702 Act36/1947) geblok word deur die diere met
die aanbevole dosis soos op die pamflet van die produkte
aangedui, te behandel. Boere wat gedeeltelike dosisse van
Berenil RTU (G2702 Act36/1947) gebruik om hulle diere te
blok loop die risiko dat die Rooiwater-parasiete weerstand
teen die middel sal ontwikkel en sal dit oor ‘n periode nie
meer suksesvol wees om die siekte te behandel nie.
Vir enige tegniese navrae kontak jou plaaslike MSD Animal
Health verteenwoordiger.
“The Science for Healthier Animals”
Treatment of Redwater
Agents that are effective to treat redwater are those that
contain diminazene, like Berenil RTU (G2702 Act36/1947) for
instance and imidokarb, like e.g Imizol (G0831 Act36/1947).
• The success of the treatment is determined by how early
in the course of the illness the animals are treated. The
prognosis of the disease in animals with advanced redwater
becomes weaker and intensive treatment by a veterinarian
might be necessary to save the animals. Even with intensive
treatment the prognosis can still be low. In the event of
an outbreak of redwater in a susceptible herd, the whole
herd must be blocked with Imizol (G0831 Act36/1947) or
Berenil RTU (G2702 Act36/1947), by treating the animals
with the recommended dose as indicated on the pamphlet
accompanying the products. Farmers that use only partial
doses of Berenil RTU (G2702 Act36/1947) to block their
animals run the risk that the redwater parasites will develop
resistance to the agent and succesful treatment of the
illness will not be possible over a period.
For any technical enquiries contact your local MSD Animal
Health representative.
“The Science for Healthier Animals”
2012
Behandeling van Rooiwater
Animals that have been treated with imidokarb (Imizol
(G0831 Act36/1947)) must not be vaccinated with Asiatic
redwater vaccine within 4 months after treatment. Likewise
animals should also not be vaccinated within 2 months
after they have been treated with diminazene (Berenil
RTU(G2702 Act36/1947)). The agents will neutralize the
infection for these relative periods and prevent animals from
becoming immunized. Once the animals have immunized,
the agents will not “sterilize” the disease as is commonly
accepted. The animal’s immunity cannot be sterilized and
only conditions that affect the animal’s immune system can
cause the animals to become susceptible to the disease
again.
June
Diere wat met imidokarb (Imizol (G0831 Act36/1947))
behandel was moet nie met Asiatiese Rooiwater entstof
ingeënt word binne 4 maande nadat hulle behandel is nie.
So moet diere ook nie binne 2 maande nadat hulle met
diminazene (Berenil RTU(G2702 Act36/1947)) behandel
is, geënt word nie. Die middels sal die infeksie vir hierdie
onderskeie periodes steriliseer en voorkom dat die diere
immuniseer. Wanneer die diere geïmmuniseer het, sal
die middels egter nie die siekte “steriliseer” soos wat
algemeen aanvaar word nie. Die dier se immuniteit kan
nie gesteriliseer word nie en slegs toestande wat die dier se
immuunstelsel affekteer kan veroorsaak dat die diere weer
vatbaar raak vir die siekte.
Animals must hence be kept tick-free during this six weeks
period before exposure to the field strain of redwater by
weekly dipping with an agent like Taktic Cattle Spray (G2535
Act36/1947), that contains amitras. It is therefore advisable
to vaccinate animals older than 8 months during the winter
months when tick numbers are low and easier to control.
BRAHM AN
behandel word voordat hulle nie koorsreaksies getoon
het nie. Indien dit gedoen word, sal beide diminazene en
imidokarb die effektiwiteit van die entstof neutraliseer
en sodoende voorkom dat die diere immuniseer. Tydens
inenting teen Asiatiese Rooiwater moet die temperatuur
van diere gemeet word vanaf dag 5 tot dag 21 na inenting
Dit neem ongeveer 6 weke vir diere om immuniteit teen die
siekte te ontwikkel na inenting. Daarom moet diere skoon
gehou word van bosluise tydens hierdie 6 weke periode
voordat hulle aan die veldstam van Rooiwater blootgestel
word, deur hulle bv weekliks met Taktic Cattle Spray
(G2535 Act36/1947), wat amitras bevat, te dip. Dit word
dus aanbeveel dat inenting van diere ouer as 8 maande in
die wintermaande geskied wanneer bosluisegetalle laer en
makliker beheerbaar is.
35
37
Code
BUSH-S
BUSH-XL
BUSH-XXL
BUSHXXXL
BVBG11-12
BVBG13-14
BVBG3-4
BVBG5-6
BVBG7-8
BVBG9-10
BVBW11-12
BVBW13-14
BVBW3-4
BVBW5-6
BVBW7-8
BVBW9-10
BVLN11-12
BVLN13-14
BVLN3-4
BVLN5-6
BVLN7-8
BVLN9-10
BVOB11-12
BVOB13-14
BVOB3-4
BVOB5-6
BVOB7-8
BVOB9-10
DRY-2XL
DRY-L
DRY-M
DRY-S
DRY-XL
GVBG11-12
GVBG13-14
GVBG3-4
GVBG5-6
GVBG7-8
GVBG9-10
GVBW11-12
GVBW13-14
GVBW3-4
GVBW5-6
GVBW7-8
GVBW9-10
GVLN11-12
GVLN13-14
GVLN3-4
GVLN5-6
GVLN7-8
GVLN9-10
GVOB11-12
GVOB13-14
GVOB3-4
Description
BUSH SHIRT - S
BUSH SHIRT - XL
BUSH SHIRT - XXL
BUSH SHIRT - XXXL
BOYS VECTOR BOT/GOLD11-12
BOYS VECTOR BOT/GOLD13-14
BOYS VECTOR BOT/GOLD3-4
BOYS VECTOR BOT/GOLD5-6
BOYS VECTOR BOT/GOLD7-8
BOYS VECTOR BOT/GOLD9-10
BOYS VECTOR BLK/WHT11-12
BOYS VECTOR BLK/WHT13-14
BOYS VECTOR BLK/WHT3-4
BOYS VECTOR BLK/WHT5-6
BOYS VECTOR BLK/WHT7-8
BOYS VECTOR BLK/WHT9-10
BOYS VECTOR LIME NAVY 11-12
BOYS VECTOR LIME NAVY 13-14
BOYS VECTOR LIME NAVY 3-4
BOYS VECTOR LIME NAVY 5-6
BOYS VECTOR LIME NAVY 7-8
BOYS VECTOR LIME NAVY 9-10
BOYS VECTOR ORANGE 11-12
BOYS VECTOR ORANGE 13-14
BOYS VECTOR ORANGE 3-4
BOYS VECTOR ORANGE 5-6
BOYS VECTOR ORANGE 7-8
BOYS VECTOR ORANGE 9-10
DRY MAC - 2XL
DRY MAC - L
DRY MAC - M
DRY MAC - S
DRY MAC - XL
GIRLS VECTOR BOT/GOLD11-12
GIRLS VECTOR BOT/GOLD13-14
GIRLS VECTOR BOT/GOLD3-4
GIRLS VECTOR BOT/GOLD5-6
GIRLS VECTOR BOT/GOLD7-8
GIRLS VECTOR BOT/GOLD9-10
GIRLS VECTOR BLK/WHT11-12
GIRLS VECTOR BLK/WHT13-14
GIRLS VECTOR BLK/WHT3-4
GIRLS VECTOR BLK/WHT5-6
GIRLS VECTOR BLK/WHT7-8
GIRLS VECTOR BLK/WHT9-10
GIRLS VECTOR LIME NAVY 11-12
GIRLS VECTOR LIME NAVY 13-14
GIRLS VECTOR LIME NAVY 3-4
GIRLS VECTOR LIME NAVY 5-6
GIRLS VECTOR LIME NAVY 7-8
GIRLS VECTOR LIME NAVY 9-10
GIRLS VECTOR ORANGE 11-12
GIRLS VECTOR ORANGE 13-14
GIRLS VECTOR ORANGE 3-4
Selling
170
185
195
200
115
115
100
100
105
105
115
115
100
100
105
105
115
115
100
100
105
105
115
115
100
100
105
105
245
225
225
225
245
115
115
100
100
105
105
115
115
100
100
105
105
115
115
100
100
105
105
115
115
100
Code
GVOB5-6
GVOB7-8
GVOB9-10
KB11-12
KB13-14
KB5-6
KB7-8
KB9-10
KBB11-12
KBB13-14
KBB5-6
KBB7-8
KBB9-10
KKB11-12
KKB13-14
KKB3-4
KKB5-6
KKB7-8
KKB9-10
KKG11-12
KKG13-14
KKG3-4
KKG5-6
KKG7-8
KKG9-10
LBB4XL
LBBL
LBBM
LBBS
LBBXL
LBSL
LBSM
LBSS
LBSSL
LBSSM
LBSSS
LBSSXL
LBSXL
LCBP2XL
LCPBL
LCPBM
LCPBXL
LF2XL
LFL
LFM
LFXL
LK2XL
LKL
LKM
LKXL
LOUNGE-L
LOUNGE-M
LOUNGE-XL
LOUNGE-XXL
Description
GIRLS VECTOR ORANGE 5-6
GIRLS VECTOR ORANGE 7-8
GIRLS VECTOR ORANGE 9-10
GIRL BUSH 11-12
GIRL BUSH 13-14
GIRL BUSH 5-6
GIRL BUSH 7-8
GIRL BUSH 9-10
BOYS BUSH 11-12
BOYS BUSH 13-14
BOYS BUSH 5-6
BOYS BUSH 7-8
BOYS BUSH 9-10
BOYS KIDDIES KNIT GOLFER BLUE 11-12
BOYS KIDDIES KNIT GOLFER BLUE 13-14
BOYS KIDDIES KNIT GOLFER BLUE 3-4
BOYS KIDDIES KNIT GOLFER BLUE 5-6
BOYS KIDDIES KNIT GOLFER BLUE 7-8
BOYS KIDDIES KNIT GOLFER BLUE 9-10
GIRLS KIDDIES KNIT GOLFER PINK 11-12
GIRLS KIDDIES KNIT GOLFER PINK 13-14
GIRLS KIDDIES KNIT GOLFER PINK 3-4
GIRLS KIDDIES KNIT GOLFER PINK 5-6
GIRLS KIDDIES KNIT GOLFER PINK 7-8
GIRLS KIDDIES KNIT GOLFER PINK 9-10
LADIES BUSH AIRFORCE BLUE - 4XL
LADIES BUSH AIRFORCE BLUE - L
LADIES BUSH AIRFORCE BLUE - M
LADIES BUSH AIRFORCE BLUE - S
LADIES BUSH AIRFORCE BLUE - XL
LADIES BUSH SAFARI - L
LADIES BUSH SAFARI - M
LADIES BUSH SAFARI - S
LADIES BUSH STONE - L
LADIES BUSH STONE - M
LADIES BUSH STONE - S
LADIES BUSH STONE - XL
LADIES BUSH SAFARI - XL
LEGACY LOUNGE LS PINE/BLACK - 2XL
LEGACY LOUNGE LS PINE/BLACK - L
LEGACY LOUNGE LS PINE/BLACK M
LEGACY LOUNGE LS PINE/BLACK XL
LIBERTY FERN - 2XL
LIBERTY FERN - L
LIBERTY FERN - M
LIBERTY FERN - XL
LIBERTY KALAHARI - 2XL
LIBERTY KALAHARI - L
LIBERTY KALAHARI - M
LIBERTY KALAHARI - XL
LOUNGE SHIRT - L
LOUNGE SHIRT - M
LOUNGE SHIRT - XL
LOUNGE SHIRT - XXL
Selling
100
105
105
160
160
135
150
150
160
160
135
150
150
85
85
70
70
80
80
85
85
70
70
80
80
245
205
205
205
225
205
205
205
205
205
205
225
225
205
185
185
205
245
225
225
245
245
225
225
245
125
120
135
140
Code
Description
MTRL
MEN TWILL LS ROYAL - L
MTRM
MEN TWILL LS ROYAL - M
MTRXL
MEN TWILL LS ROYAL - XL
MTS2XL
MEN TWILL SS STEEL GREY - 2XL
MTSG2XL
MEN TWILL LS STEEL GREY - 2XL
MTSGL
MEN TWILL LS STEEL GREY - L
MTSGM
MEN TWILL LS STEEL GREY - M
MTSGXL
MEN TWILL LS STEEL GREY - XL
MTSL
MEN TWILL STEEL GREY - L
MTSM
MEN TWILL SS STEEL GREY - M
MTSR2XL
MEN TWILL SS ROYAL 2XL
MTSRL
MENS TWILL SS ROYAL L
MTSRM
MEN TWILL SS ROYAL - M
MTSRXL
MEN TWILL SS ROYAL - XL
MTSXL
MEN TWILL SS STEEL GREY - XL
MTT2XL
MENS TRAIL TAN - 2XL
MTTL
MEN TRAIL TAN - L
MTTM
MENS TRAIL TAN - M
MTTXL
MEN TRAIL TAN - XL
MVG-L
MEN VECTOR GOLFER - L
MVG-M
MENS VECTOR GOLFER - M
MVG-S
MENS VECTOR GOLFER - S
MVG-XL
MENS VECTOR GOLFER - XL
MVG-XXL
MENS VECTOR GOLFER - XXL
MVG-XXXL MENS VECTOR GOLFER - XXXL
NAVY-S
SHOW JACKET NAVY - S
NAVY-XXL
SHOW JACKET NAVY - XXL
NAVY-XXXL SHOW JACKET NAVY - XXXL
NAVY-XXXXL SHOW JACKET NAVY - XXXXL
NJCB2XL
NEWPORT JACK COCOA BROWN 2XL
NJCBL
NEWPORT JACK COCOA BROWN - L
NJCBM
NEWPORT JACK COCOA BROWN - M
NJCBXL
NEWPORT JACK COCOA BROWN - XL
PHEMPGB-XL SHIRTS KHAKI - XL
PHEMPGB-XXLSHIRTS KHAKI - XXL
PMK
YARD STICK
PPL
STICKER - RED
PPN
CAP - MATERIAL (& LOGO)
PPR
STICKER - WHITE
PSA
PET GREY STON
PSC
PET BLACK STONE
PSD
PET NAVY STONE
RJD2XL
REVERSIBLE JACKET DRIFTWOOD 2XL
RJDL
REVERSIBLE JACK DRIFTWOOD - L
RJDM
REVERSIBLE JACK DRIFTWOOD - M
RJDXL
REVERSIBLE JACK DRIFTWOOD - XL
SGB
STANDARD COMMEMORATIVE JOURNAL
SMF2XL
SLEEVELESS MICRO FLEECE - 2XL
SMFL
SLEEVELESS MICRO FLEECE - L
SMFM
SLEEVELESS MICRO FLEECE - M
SMFS
SLEEVELESS MICRO FLEECE - S
SMFXL
SLEEVELESS MICRO FLEECE - XL
SSB2XL
MEN SHOULDER STRIPE BOTTLE - 2XL
SSBL
MEN SHOULDER STRIPE BOTTLE - L
SSBM
MEN SHOULDER STRIPE BOTTLE - M
SSBXL
MEN SHOULDER STRIPE BOTTLE - XL
STONE-XXL SHOW JACKET STONE - XXL
T01
BIBBY
VGB
COMMEMORATIVE JOURNAL
(SS- SHORT SLEEVE, LS - LONG SLEEVE)
Selling
205
205
225
215
215
205
205
225
195
195
215
195
195
215
215
330
300
300
300
165
165
165
180
180
195
210
210
210
210
300
300
300
300
185
195
185
15
55
15
65
65
65
605
550
550
605
150
185
170
170
170
185
185
170
170
185
210
70
850
2012
Selling
145
195
175
175
195
360
300
300
300
330
300
300
300
330
380
380
380
165
165
165
180
180
165
165
180
175
155
155
175
225
205
205
225
225
205
205
225
185
185
205
225
225
205
205
225
210
195
195
210
185
170
170
185
330
300
300
330
415
380
380
415
415
380
380
415
225
June
Description
LOUNGE SHIRT - XXXL
LEGACY CHECK SS PINE/BLACK 2XL
LEGACY CHECK SS PINE/BLACK L
LEGACY CHECK SS PINE/BLACK - M
LEGACY CHECK SS PINE/BLACK XL
LADIES TRAIL BLOUSE TAN - 4XL
LADIES TRAIL BLOUSE TAN - L
LADIES TRAIL BLOUSE TAN - M
LADIES TRAIL BLOUSE TAN - S
LADIES TRAIL BLOUXE TAN - XL
LADIES TRAIL BLOUSE FOSSIL - L
LADIES TRAIL BLOUSE TAN - M
LADIES TRAIL BLOUSE FOSSIL - S
LADIES TRAIL BLOUSE FOSSIL - XL
LADIES TECHNO JACKET BLACK-L
LADIES TECHNO JACKET BLACK-M
LADIES TECHNO JACKET BLACK-S
LADIES VECTOR GOLFER - L
LADIES VECTOR GOLFER - M
LADIES VECTOR GOLFER - S
LADIES VECTOR GOLFER - XL
MEN AMBASSADOR LS KHAKI - 2XL
MEN AMBASSADOR LS KHAKI - L
MEN AMBASSADOR LS KHAKI - M
MEN AMBASSADOR LS KHAKI - XL
MEN AMBASSADOR SS KHAKI 2XL
MEN AMBASSADOR SS KHAKI - L
MEN AMBASSADOR SS KHAKI - M
MEN AMBASSADOR SS KHAKI - XL
MENS BUSH AIRFORCE BLUE - 2XL
MENS BUSH AIRFORCE BLUE - L
MENS BUSH AIRFORCE BLUE - M
MENS BUSH AIRFORCE BLUE - XL
MENS BUSH SAFARI - 2XL
MENS BUSH SAFARI - L
MENS BUSH SAFARI - M
MENS BUSH STONE - 2XL
MENS BUSH STONE - L
MENS BUSH STONE - M
MENS BUSH STONE - XL
MENS BUSH SAFARI - XL
MEN CIVIC LS NAVY - 2XL
MEN CIVIC LS NAVY - L
MENS CIVIC LS NAVY - M
MEN CIVIC LS NAVY - XL
MEN CIVIC SS NAVY - 2XL
MEN CIVIC SS NAVY - L
MEN CIVIC SS NAVY - M
MEN CIVIC SS NAVY - XL
MEN SHOULDER STRIPE BLACK - 2XL
MEN SHOULDER STRIPE BLACK - L
MENS SHOULDER STRIPE BLACK - M
MEN SHOULDER STRIPE BLACK -XL
MEN TRAIL FOSSIL - 2XL
MEN TRAIL FOSSIL - L
MEN TRAIL FOSSIL - M
MEN TRAIL FOSSIL - XL
MEN TECHNO JACK RUST/BLOCK 2XL
MENS TECHNO JACK RUST/BLACK - L
MENS TECHNO JACK RUST/BLACK - M
MEN TECHNO JACK RUST/BLACK - XL
MEN TECHNO JACK SLATE/BLACK 2XL
MEN TECHNO JACKET SLATE/BLACK - L
MEN TECHNO JACK SLAT/BLACK - M
MEN TECHNO JACK SLATE/BLACK - XL
MEN TWILL LS ROYAL - 2XL
BRAHM AN
Code
LOUNGEXXXL
LSPB2XL
LSPBL
LSPBM
LSPBXL
LTB4XL
LTBL
LTBM
LTBS
LTBXL
LTFL
LTFM
LTFS
LTFXL
LTTBL
LTTBM
LTTBS
LVG-L
LVG-M
LVG-S
LVG-XL
MAK2XL
MAKL
MAKM
MAKXL
MASK2XL
MASKL
MASKM
MASKXL
MBAB2XL
MBABL
MBABM
MBABXL
MBS2XL
MBSL
MBSM
MBSS2XL
MBSSL
MBSSM
MBSSXL
MBSXL
MCN2XL
MCNL
MCNM
MCNXL
MSN2XL
MSNL
MSNM
MSNXL
MSSB2XL
MSSBL
MSSBM
MSSBXL
MTF2XL
MTFL
MTFM
MTFXL
MTJB2XL
MTJBL
MTJBM
MTJBXL
MTJS2XL
MTJSL
MTJSM
MTJSXL
MTR2XL
39
2012
Junie
BRAHM AN
40
Genetic improvement benefits
commercial producers
Dr Michael Bradfield
1. Introduction
In many livestock species genetic progress can occur at a rate of 1-2% per trait per annum and is
cumulative. This rate of progress is easily achievable in the dairy, pork and chicken industries.
Despite environmental constraints, this rate of progress is also achievable in the beef industry and
the value would be worth many millions of rand to our industry. However, to become a leader in
Africa (if not the world) in the field of animal breeding, South African Brahman breeders face three
main challenges;
a) The first is getting our commercial producers to understand the potential monetary value that
modern breeding methods can add to the genetic potential of their herds and how it translates
into financial gain.
b) The second challenge is for our Stud Industry to move away from using only old fashioned methods
for the selection of superior Seedstock. Here I am talking about using purely visual assessment