EPD
Expected Progeny Differences
Expected Progeny Differences (EPD) are the most accurate and effective tool available for comparing genetic levels. In using EPD, the difference between two sires' EPD represents the unit difference expected in the performance of their progeny.
For example:
Sire A has an EPD of +10 units
Sire B has an EPD of -5 units
We would expect a 15-unit difference in their progeny (moving from -5 to +10 yields 15 units).
Key to using EPD is knowing what units they are expressed in. For example, if the above case referred to weaning weight EPD, A would be expected to sire 15-pounds more weaning weight than B. If calving ease were the trait, A would be expected to sire 15-percent more unassisted births in first-calf heifers; in other words, if B sired 30 assists in a group of 100 heifers, we'd expect A to require 15 assists. Review the Trait Chart below for information on how each trait is expressed.
A percentile-ranking chart is required to determine where a bull's EPD rank him relative to other bulls in the breed.
Trait Definitions
Growth & MAternal Traits
Intake & Carcass Traits
2020 Estimated Progeny Equivalents
An estimated progeny equivalent is the average number of progeny records it would take to see an equivalent change in accuracy from a genomic test. For example, if a non-parent animal is genotyped, the accuracy of his/her EPD is akin to an animal that has already produced 5 offspring with a carcass weight record (see table below).
Overtime, these estimates will change as statistical models are improved, the number of phenotypes increases, and the information from genomic data improves.