TRIED & TRUE
source
for
cattle
continued from page 64
Drs. Mahdi Saatchi and Dorian Garrick, while they were scientists
at Iowa State University. Drs. Saatchi and Garrick first used the
50,000 markers to determine a subset of weighted markers that are
highly associated with economically-relevant traits in beef cattle with
consistent effects across breeds. Because the IGS evaluation is for
multiple breeds, it is important to remove markers with inconsistent
effects or no effects in different breeds. The Saatchi and Garrick
research also found that utilizing genotypes on animals of multiple
breeds consistently increased the accuracy of prediction within a
particular breed when compared to limiting DNA utilization to only
animals of a particular breed.
5. Why are some traits influenced by markers and others are not?
The genetic architectures of various traits are different. Some are
controlled by few genes with large effects and some are controlled
by many small-effects genes. In the current DNA profilers, there are
some markers with high correlations with corresponding genes for
some traits and low correlations with others. That’s why we see the
different DNA added values for different traits. It is hard to change
the genetic architecture of a trait. But, new DNA profilers or future
technologies may help to improve the value of DNA information for
such traits. Furthermore, some maternal traits, like Maternal Calving-
Ease and Milk, are difficult to predict with genomics because there
are so few females genotyped. Increasing the number of cows and
heifers genotyped will improve the ability to use genomics to predict
maternal traits.
We were breeding Lim-Flex before Lim-Flex were cool.
Nearly 40 years ago we recognized the advantages of
Limousin x Angus cattle and have been breeding them ever since.
We strive to produce bulls and females that combine structural
soundness with performance, maternal and carcass traits.
6. Will genomic testing replace the need to submit
phenotype records?
No, reporting actual records is critical. The value of genomic
predictions increases as the amount of phenotypic information
increases. Furthermore, at this point, animals cannot achieve high
accuracy with genomic data alone. High accuracy EPDs are only
achievable by collecting many phenotypic records on offspring.
BALL RANCH 7. H
ow do we know predictions via BOLT are better than
the previous system (Cornell software)?
The IGS evaluation team has conducted a series of validations to
compare the BOLT system to the Cornell system. BOLT-derived
EPDs had higher correlations to birth, weaning and yearling weights
(0.34, 0.29 and 0.26, respectively) than the Cornell derived EPDs
(0.27, 0.19 and 0.20, respectively). Furthermore, there was a larger
difference in average progeny performance (birth, weaning and
yearling) of the top 1% compared to the bottom 1% animals in the
BOLT derived EPDs compared to the Cornell calculated EPDs.
Both validations suggest the BOLT EPDs align better with the actual
phenotypes than the Cornell EPDs.
John & Justin Ball
Cell: 405/258-3616
Office: 405/258-1511 8. Why do some animals have substantial changes in their indexes?
Though the correlations between the previous (Cornell derived)
EPDs/indexes and the BOLT derived EPDs/indexes are relatively
Breeding Age Bulls and Females for sale
Reasonably priced and available on a
first-come, first-served basis.
CHANDLER, OK
5-1/2 MILES NORTH OF I-44 ON HWY. 18
www.limflex.com
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• JANUARY 2020