April 1 2015 06:44 AM

Genomics is taking away some of the guesswork.

Some read the milk meter. Others admire cow families. A few "just know" that a heifer or cow will be great.
With dairy cattle, producers use various information sources to determine the caliber of the animals in their herd: pedigree, performance and progeny. Holstein, Jersey, Brown Swiss and Ayrshire breeders have a fourth source, genomics.

A pedigree is only as good as the data sources that feed it. Not all herds register, conduct type appraisal or DHI test. When information is not present, it limits our decision-making ability.

Previously, the information with the most credibility was progeny data, which included type appraisals and official milk records. However, 2013 data showed nearly 25 percent of animals genotyped were previously misidentified. With that level of inaccuracy at the herd level, how much confidence can be placed on progeny data when one-quarter of a bull's daughters might not be his daughters?

Providing accurate information without environmental bias, the first genomic results were released in January 2009. Since then, formulas have been fined-tuned. "Preferentially choosing mates that accentuate strengths and help correct weaknesses is an important component of the use of genomic data," stated Jason Osterstock, D.V.M., in the 2014 AABP Proceedings.

With these resources, particularly genomics, producers can more accurately decide which animals to keep for breeding purposes and which to cull. In addition, genomics allow producers to identify and focus on the top females. They can use higher-valued bulls, sexed semen, embryo transfer or in vitro fertilization on the upper end to make the fastest genetic progress, which they hope translates into higher yielding, healthier and longer-lived cows.

The lower genetic animals can be sold, used as recipients in an embryo transfer program or bred to beef bulls. With early genomic testing, these heifers can be sold before feed costs accumulate on marginal producers. If the goal is expansion and the facilities are available, these animals can remain in the herd to build inventory. They still are contributing herd members but will not provide the most aggressive genetic gains.
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The author is the online media manager and is responsible for the website, webinars and social media. A graduate of Modesto Junior College and Fresno State, she was raised on a California dairy and frequently blogs on youth programs and consumer issues.