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The Value of DNA Information in the Multi-breed
Genetic Evaluation powered by BOLT
By Mahdi Saatchi, Rohan L. Fernando, Lauren Hyde, Jackie Atkins, Steve McGuire, Wade Shafer, Matt L.
Spangler, and Bruce Golden, IGS Genetic Evaluation Team and Consultants.
DNA profiles provide additional
information about the genetic
merit of a DNA tested animal
and increase the accuracy of
EPDs, which are called Genomic
Enhanced EPD or GE-EPDs. In
the IGS Single-step process,
the DNA marker genotypes are
directly incorporated into the
genetic evaluation along with
the phenotypes (performance
data) and the pedigree. As a
result, the DNA information
has an impact not only on the
genotyped individual, but
also on all the relatives of that
genotyped individual. This
allows for the DNA information
Figure 1
110 | JUNE/JULY 2018
to improve the accuracy of
non-genotyped relatives.
To measure the impact of DNA
information on accuracies
of GE-EPDs in the IGS single-
step genetic evaluations, we
compared the average BIF
accuracies of GE-EPDs of DNA
tested young animals (born
in 2016 with no progeny) to
the average BIF accuracies
of non-genotyped sires born
in 2010-2014. Only sires with
non-genotyped calves were
used for this comparison.
We found that the average
BIF accuracy of GE-EPD for a
DNA tested young animal is
equivalent to the average BIF
accuracy of a non-genotyped
sire with 21, 22 and 24 calves
with observed phenotypes for
birth, weaning and yearling
weights, respectively (Figure
1, where a horizontal line cross
a curve for a specific trait (e.g.
red line and blue curve cross
each other at the data point
correspond to y(accuracy)=0.46)
and x(progeny) = 21 for
birth weight)). The progeny
equivalent (PE) for direct
calving ease was 15 and it
was only 3 for total maternal
calving ease due to limited
genotypes on cows. The PE for
milk and stayability were 18
and 25, respectively (Figure 1).