Using EPDs in sire selection

As collegiate athletes enter their respective sport’s draft, performance data is often a factor that coaches look at to decide which recruit will be the best match for the team.

In much the same way, expected progeny differences (EPDs) can be helpful to beef producers in selecting the right sire for the herd, according to Dan Moser, K-State beef cattle geneticist and associate dean of academic programs for the College of Agriculture.

Moser was a guest on a recent Cattle Chat podcast that addressed a listener question about when to prioritize information from the EPD versus just looking at the individual data for a particular trait, such as weaning weight or yearling weight.

“If the individual animal’s data has been submitted to the breed association, then the EPD is always going to be more accurate than just the individual performance measure because more information is included in calculating the EPD,” Moser said. “The EPD calculation will also factor in pedigree information from the parents and siblings and in some cases, it will also include genomics (a DNA test that predicts the animal’s genetic traits).”

Moser said that even if the EPD has a low accuracy, the trait measurement is already included in the calculation, so producers can just use the EPD to gather information about that trait.

How EPDs are calculated varies among the cattle breeds, so Moser said producers need to look at the possible change table for each trait to see how much risk there will be with a particular level of accuracy.

“Even though the accuracies appear low, by looking at the possible change table, producers can calculate the amount of risk they want to take on for any given trait,” Moser said. “The accuracy is reflecting the information that is available at the time of calculation and the prediction may change as more information comes into the equation.”

An example of this is when the animal’s progeny’s performance data is added to the calculation, Moser said.

“While the genetics of the bulls don’t change over time, the EPDs change as more information about the bulls is added to the equation,” K-State veterinarian Brad White said.

Breeding decisions can have long-term effects on the herd, K-State veterinarian Bob Larson said.

“Take the time to look at the data, because the best cowherds are built with a lot of good decisions made year after year,” Larson said. “Just as in baseball, your goal is to win a lot of games, but that doesn’t mean you’ll hit a home run on every decision you make.”

To hear the full discussion, listen to Cattle Chat on your preferred streaming platform.