One of the most significant advancements in beef cattle breeding in recent years has been the addition of genomic information into genetic evaluations that produce expected progeny differences (EPDs). By adding genotypes from DNA data to an already extensive database of phenotypic and pedigree information, prediction accuracy has been dramatically improved, especially for young animals that haven’t yet produced calves.

Instead of waiting years for a bull or cow to accumulate progeny records, genotyping provides a similar level of accuracy to those achieved with progeny records earlier in life. This advantage is quantified through a concept known as progeny equivalents (PE). PEs measure how much additional information a genotype contributes compared to traditional pedigree and performance records. In short, genotyping doesn’t replace traditional methods and phenotypes; it complements them, improving selection accuracy of young animals and accelerating genetic progress of the beef herd.

When a young animal is genotyped, a network of other genotyped animals with individual phenotypes and progeny records is leveraged, specifically those animals closely related at the DNA level. By combining genotypes with phenotypes and the pedigree, we can predict EPDs with greater accuracy. This relationship boosts the accuracy of that young animal’s EPDs, even before progeny records can be recorded; which is useful for reducing selection risk when making selection decisions on young animals. This helps to make more accurate selection decisions earlier.

What do progeny equivalents represent?

Progeny equivalents tell us how many offspring with phenotypic records an animal would need to have in order to reach the same level of accuracy as provided by genotyping.

As an example, a non-genotyped bull would need approximately 25 progeny with weaning weight records, in proper contemporary groups, to reach a similar level of accuracy of a genotyped bull without phenotypic records (Figure 1). In other words, genotyping provides the same level of information equivalent to having about 25 calves, or a first calf crop, with weaning weight records. This level of information allows you as a producer to make more informed selection decisions without having to wait for the calf crop from that sire. With genomic technology, you can have a higher accuracy on EPDs for a young animal as early as a few weeks after the calf is born if samples are submitted shortly after birth.