Beef Genetic Management Guide - Angus Journal

By: Al Kuck, Vice President, Beef Programs
DNA marker technology has been advancing rapidly since the
first markers were discovered in 1989. GeneSTAR ® was first
introduced in 2000 as a single marker test for marbling. In 2004
GeneSTAR
Born:
introduced three more marbling and
Yrlg.
three
Frame:
tenderness
markers,
Birth Weight:
in 2006 four feed efficiency markers
Mature
were
Frame:
incorporated.
Rankings
205 Days:
were expressed as stars which indicated
Scrotal:
the presence
or absence 365 Days: of the desirable gene. In this Beef Genetic Tattoo: Management
Guide Mature: you will find Molecular Value Predictions Calving Ease (MVPs) Rating: listed
under Owned each By: bull. It is the next logical iteration of genetic marker
These Molecular Value Predictions are a significant improvement
over the star system previously used by GeneSTAR. It is a more
powerful tool because it provides direct information on the expectations
when using a sire. It will be most valuable on animals that do not
have a progeny proof or with relatively little progeny performance
data. In our listings within the Beef Genetic Management Guide,
we are also providing “percentile rankings” which indicate how the
animal ranks within the respective breed. As an example, an animal
in the 10th percentile would be better than 90% of the breed.
selection. These predictions for feed efficiency, marbling and
tenderness include the original 11 validated markers plus an
additional 45 markers.
The development of GeneSTAR MVPs followed a four step process:
1. Discovery - identify panels of markers that are significantly
correlated with one or more cattle groups with data for
commercially important traits.
2. Statistical methods - incorporate individual markers into
larger marker panels to develop the MVP values.
3. Evaluation - each marker panel is evaluated in separate
cattle groups to see if it predicts the trait as well as it does
in the original discovery population.
4. Third Party Validation - the National Beef Cattle Evaluation
Consortium acts as a third-party agency to validate DNA
marker technology
Trait Definition Units
Feed
Efficiency2
Marbling3
Feed Efficiency Marbling Tenderness
1.03 -0.2 -0.38
100% 100% 30%
Difference between an
animal’s actual and expected
feed intake based on its body
weight and growth rate
Degree of intramuscular
fatness in the longissimus
dorsi (ribeye) muscle
lbs./day
Marbling
Score 0 – 9
MVP
Range*
Min: -3.17
Max: 2.38
Min: -1.00
Max: 1.11
While these new GeneSTAR MPVs are a much more useful tool,
it is only the beginning of much bigger programs to come from
Pfizer Animal Genetics. Cattle producers will have access to a new
suite of traits in 2010. This will come with the first commercial
genomic predictions based on the high density BovineSNP50 chip.
This chip will look at 50,000 individual SNP markers scattered
throughout the cattle genome to predict a wide variety of traits.
This very large panel of markers will yield much higher levels of
accuracy of prediction. Validation studies are now underway
and we would expect to have the test available in early 2010.
The information will continue to be delivered using the MVP
platform. Some of these will enhance the reliability of traditional
EPD traits that we are all familiar with. Other MPVs will be
for traits that are expensive and difficult to measure, and
likely beyond the scope of most breeders to measure, yet are
economically important.
Average %
Reliability
30%
26%
We believe this new technology will be useful
for producers in both the commercial and
seedstock arenas. The commercial producer can
identify his top production cows, and they can be
bred with female-sorted semen to provide future
replacements. The remainder can be bred to malesorted
semen to provide a higher percentage of
steers, taking advantage of the price differential.
The seedstock producer can put top ranking animals
into flushing programs, or breed top cows to male
or female-sorted semen, depending on the needs
of his customers. The remainder can be utilized as
recipients or bred to a male-sorted terminal sire.
Tenderness
Force required to shear a
cooked steak after
postmortem aging
W-B Shear
Force (lbs.)
Min: -1.04
Max: 1.89
* The closer the MVP value is to the highlighted Minimum or Maximum in each row,
the more favorable the result. The reliability value is expressed a a percentage of
the maximum accuracy available.
49%
The potential for management of rapid genetic progress
will be unlike anything we have seen before! Watch
for announcements on availability of this testing.
Contact your Genex representative or Genex
customer service (888-333-1783) for a test kit.
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