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A N I M A L H E A L T H
Independent Veterinary Consultant
And in association with Willows Veterinary Group
KAT E BURNB Y
B V S c , C e r t CHP, MRCV S
About
Genomics
I
t was 1953 - Josef Stalin died of a stroke, Hugh Hefner published the first
issue of Playboy magazine, Queen Elizabeth II took her coronation oath
and, in February, Watson & Crick described the structure of DNA.
The sum of our DNA describes life - it makes
up our genome. Each person and animal has
a unique genome - although we also have
large portions of our DNA in common. The
time and cost required to study the genome
continues to reduce.
Improving farm performance and health through
genomics opens up a wealth of opportunities
for livestock farmers. A drive has been fuelled to
develop technologies and computational models
to use genetic information to study biological
problems and improve animal breeding.
In July we were fortunate to have a visit from
Dr. Kent Anderson from Colorado, USA of
Pfizer Animal Genetics. Kent spoke to a
number of XLVets at several venues, including
the Willows Vet Group, about Pfizer’s current
genomic products and about their exciting
research and development plans. The most
applicable technologies used do not sequence
the whole genome - instead they focus on
‘DNA-markers’ - small sections of DNA
(‘SNPs’) that are identified and mapped
from a sample by an automated process.
The number of SNPs that are mapped for a
sample may vary from a single marker to over
120,000 markers. The main consideration
regarding the number of SNPs mapped is cost.
DNA marker testing enables the relationship
between animals to be determined e.g. for
parentage validation. Markers for specific
genetic diseases can be checked for e.g.
CVM and markers for some simple traits
like red vs. black coat colour are also a
well-established use for the technology. In the
USA a test called GeneSTAR ‘HD50k’ has
been developed and used within the Angus
breed. This test provides predicted breeding
values (MPVs) for 13 production traits after
analysing just over 50,000 markers.
To set up tests like the HD50k they need DNA
and conventional records e.g. compare the
markers from sires with high conventional
breeding values for average daily gain to sires
with average scores for this trait. In this way
markers can be identified that predict animals’
likely breeding values. As you can appreciate,
far from being made obsolete, recording
performance has never been more important.
Integration of DNA marker predictions with
traditional ancestry, individual and progeny
data can result in more rapid genetic progress.
The Future?
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Integration of genomic breeding values into
industry standard economic breeding values
derived from conventional proving schemes
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Improved selection for traits that are hard to
select for e.g. calving ease
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Customised breeding values depending on
economics in market looking at for example
marbling, of high importance in US, but of
less importance currently in UK with its
different grading system
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Extension of tests available to more breeds
and inclusion of more traits
A word of warning - as we know not all
traits are universally applicable to profitability
especially in different production systems.
Farmers should take advantage of veterinary
help to interpret and utilise the values that
arise from genomic testing.
There are at least 18,000 UK cattle
currently known to be without valid
passports, and therefore legally
un-saleable, according to the BCMS.
As you will know, an appeal against a
rejected passport application must be
accompanied by proof of parentage
from an authorised source. BCMS can
be referred to for a detailed account of
the process.
To avoid last minute panic as you prepare
animals for sale and a missing passport
cannot be found, check your records now.
If any are missing, they can be applied
for and replaced in good time.
For the parentage check, samples are
required from the animal itself and the
dam. Kits for this purpose from Pfizer
Animal Genetics are available from your
veterinary practice and your vet will come
and take the samples. Results are posted
directly back to you from the laboratory.
PSST…
DON’T GET CAUGHT
BY PARENTAGE TRAP
AUTUMN 2010 ISSUE
LIVESTOCK MATTERS
6
Benefits
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Test easily for genetic diseases
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Establish family relationships
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Generate breeding values for traits
that normally require large numbers
of progeny e.g. calving ease
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Generate predicted breeding values for
traits that are hard to measure e.g. dry
matter intake
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Speed up genetic gain
Current uses of Genomics
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Parentage testing - e.g. BCMS scheme
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Genetic screening for specific genetic
diseases e.g. CVM
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Screening for some simple inherited traits
e.g. red vs black coat colour
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Genomic screening for traits within some
breeds e.g. Angus
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Some genetics companies utilise
genomics e.g. L.I.C.