– Garth Ruff, Beef Cattle and Livestock Marketing Field Specialist, OSU Extension
Could DNA testing improve your ability to select seed stock?
I’ve always said that the best part of working in Extension, is that every day is different. I’ve spent most of the last three months traveling the state teaching programs, attending meetings, and talking to cattle producers. This winter one of the topics that was often discussed with cow-calf clientele was how to interpret genetic data to consider when making a bull selection decision. A couple of the common themes were:
- There is so much genetic information on cattle today, how do we decide what’s important? Without context and an ever-increasing number of EPD’s in the different breeds, it appears there is potential for data overload.
- How do genomics impact EPD’s and selection decisions?
At a basic level we can’t discount traditional ways of evaluating bulls where:
- Good EPDs + good visual appraisal = Useful animal.
- Poor EPDs + good visual appraisal = Unusable animal.
- Good EPDs + poor visual appraisal = Unusable animal.
We often follow that line of thinking with giving the benefit to visual appraisal due to the fact that a herd bull has to be structurally functional to go out and breed cows.
In short, feet and set to the legs still matter, as do scrotal size and muscle shape. I often hear that buyers do not like fat, over conditioned bulls. Visual appraisal is still the best wat to evaluate bull condition.
So visual appraisal aside, where do we go from there?
When evaluating genetic data, each individual production system will determine what genetic traits that should be emphasized. For example, a producer selling feeder cattle may choose to weight growth EPD’s higher than a seedstock producers who may give preference to maternal EPD’s. However, balanced trait selection is often the goal.
What about genomic enhanced, GE-EPD’s?
A group of researchers led by Dr. Charles Martinez at the University of Tennessee, have done some research in the area of evaluating what data that potential bull buyers use. They did so by interviewing perspective bull buyers, having them predicting the price of a bull given a production scenario. Dr. Martinez’a lab has also used eye tracking software to track what those buyers actually looked at in terms of data and information in the sale catalog.
In summary what they found is that bull buyers often experience information overload when looking through a catalog and that the order that information is presented in the catalog matters. Providing index data can be helpful to producers, if the application of the data is understood.
In the price prediction project, farmers used EPD’s, GE-EPD’s, percentile rankings, and visual appraisal to make decisions. GE-EPD’s were used less than traditional EPD’s and visual appraisal was used the most. This suggests there is still need for education in how to utilize genomic data and accuracy of EPD’s.
Performing a genomic panel animals will increase the accuracy of an EPD. Understanding the impact of increased accuracy and heritability can improve the rate of genetic progress in our herds. Remember that a bull represents 50% of the genetics in a calf crop. In today’s cattle market a good bull buying decision can be significant difference of several dollars come time to market a calf crop.
EDITOR’s NOTE: For more details regarding genomics and the merit of DNA testing, see John Yost’s presentation embedded below from Session 4 of the 2025 OSU Extension Beef Team’s Virtual Beef School entitled Implementing Genomic Testing on Your Farm.