Soundness is recognized as an important trait for a profitable commercial cow-calf operation, and Angus, Gelbvieh, Red Angus, and Simmental Associations have all had active research projects looking into producing genetic predictions for feet and legs.
In the case of Angus, they first started exploring objective selection for foot structure in 2014, and the American Angus Association has been the first to release foot score genetic predictions with their recent release of foot angle and claw set EPDs (expected progeny differences).
These new EPDs represent a research run to study the predictions’ efficacy prior to going into the weekly production runs. The genetic predictions are the result of the analysis of over 12,000 foot scores for both the foot angle and claw set, which had been collected since 2015 from 30 states.
The EPDs represent the foot angle and claw set on yearling animals, but animals of all ages are put in the analysis and used in a repeated measures model. However, the yearling contemporary group (CG) determines their CG for measures at all ages. Angus Genetics, Inc. (AGI) president Dr. Dan Moser says they are contemporary grouped this way because of the impact of nutrition on a growing animal has on its lifetime soundness. In the analysis, they were also able to incorporate genomics with their new Single Step model to better define the relationship between animals and increase the accuracy of the predictions.
The foot scores range from 1 to 9 for both traits with 5 being ideal (see figure). However, there were so few observations from 1 through 4 that only scores 5 through 9 were used in the analysis.
AGI found foot angle and claw set to be moderately heritable, each at .25. This means genetic progress can be made through selection. According to Moser, “The heritability was higher than we expected based on work done in Australia. We suspect that has to do with growing cattle being fed harder in the U.S.” Interestingly, foot angle and claw set were only genetically correlated at .22, meaning they are different traits that need to be analyzed separately.
The average EPD is .5 for both traits with the lower the EPD the better. Moser said, “Most of the EPDs fall between .3 to .7, but they range from .22 to 1.21.”
The Angus Association released the genetic predictions on all AI (artificial insemination) sires with .40 accuracy or above to the public on Jan. 30. These sires’ EPDs can be found at www.angus.org. In addition, all producers who submitted data received EPDs on those cattle and their parents.
According to Moser, they have had good feedback. “The response has been very positive. People who thought certain cattle lines had problems probably did.”
The research run may be repeated if adequate new data comes in to warrant one. For the foot score genetic predictions to move into production, the association wants to see a commitment to data submission by the membership. They will also further study the model looking for things like correlated traits that will help improve the accuracy of the genetic predictions. If it is moved into production, predictions will be calculated weekly using Angus’ advanced Single Step model.
Moser emphasizes the need for volumes of quality data. Angus has charts and video tutorials available on their website on how to score feet. It is important that the same person or team evaluate the cattle’s feet within a herd in a given year. With different people scoring, they each might have different variation resulting in poor data.
Producers are encouraged to collect data on their yearlings between 320 to 440 days when complete contemporary groups are available. They can then score mature animals on a yearly basis. The older animals will have more variation, so they supply useful information.
Although scores 1 through 4 were not used in this research run, producers are encouraged to submit the data on animals that fall in this range. Only when the association gathers critical mass on these lower scores can it be determined their impact on the analysis.
Where Angus has led the industry in collecting field data, Gelbvieh, Red Angus, and Simmental have been actively collecting research data. Kansas State University has been the primary research institution for them, and they too are looking at releasing results shortly.
The industry has identified a need—to make cattle sounder—and the breed associations have responded. Soundness is an important trait especially as it relates to longevity. Commercial cows require multiple calves to break even, and their ability to stay in the herd is the biggest driver of commercial cow-calf profitability. The fact that foot angle and claw scores are heritable means objective genetic predictions can be calculated and genetic progress can be made through selection. — Dr. Bob Hough, WLJ correspondent
