Performance Line
What Does Genomic Testing Mean
for You?
By Tonya Amen, National Center for Beef Excellence
In addition to classic pedigree and performance
data, genomic profiles provide another source
of information that gives an earlier indication
about the genetic merit of tested animals. While
valuable for all traits of interest, genomic tests
are especially helpful for those traits in which the
animal itself will never have a phenotype (like
carcass traits), or traits that take many years to
measure (like Heifer pregnancy or the longevity
of a bull’s daughters). This article seeks to help
you understand the value of your investment in
genomic profiles and will hopefully give you tools
to help discuss it with your commercial customers.
In the IGS Single-step genetic evaluation,
genotypes are now incorporated directly into
the genetic evaluation along with performance
weights and measures as well as pedigree. Due to
this direct incorporation, DNA information has an
impact not only on the genotyped individual but
also on all the relatives of the genotyped animal.
As a result, DNA information can improve the
accuracy of expected progeny differences (EPDs)
for non-genotyped relatives, adding to the value
of your genomic investment compared to the
previous post-evaluation blending methodology.
For birth weight, weaning weight and yearling
weight, they found that non-genotyped sires
had to have 21, 22, and 24 calves with weights
reported for those traits in order to have the
same level of accuracy as the genotyped non-
parents. This measure of the power of a genomic
test is referred to as a progeny equivalent.
The table below shows progeny equivalent
values for additional traits. You’ll observe that for
important traits like longevity (reported as the
Stayability EPD), genomic data has the potential
to greatly increase the accuracy of EPDs. For the
MILK EPD, a sire would need weaning weights
reported on 18 of his daughters’ calves in order to
achieve the accuracy achieved with a genomic test.
For your customers, purchasing bulls with GE-
EPDs will allow them to make selection decisions
with less risk due to the increased accuracy of
a non-parent animal’s EPDs. For example, the
progeny equivalent for calving ease direct (CED)
is 15, which means that to achieve the same
level of accuracy added by a genomic test, you
would need to have calved and reported scores
on 15 heifers bred to a non-genotyped bull.
Discussing increases in accuracy values associated
with EPDs can be a bit of a nebulous concept;
but describing the value genomics adds in terms
of progeny equivalents is much more practical,
how many calves worth of data was added? I
To gauge the impact of genomic information
on EPD accuracies, our partners at International
Genetic Solutions (IGS) compared the average
accuracy of genomically enhanced (GE) EPDs
from genomically-tested non-parents to the
average EPD accuracy of non-genotyped sires.
Trait CE CEM BW WW YW MILK STAY
Progeny
Equivalents 15 3 21 22 24 18 25
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