What are EPDs?

Quite simply, EPDs predict performance differences we expect to see in an animal’s progeny due to the inherited genetic merit received from that particular parent versus other parent animals with different

EPDs. The classic example:

Bull A has a BW EPD of +1 and

Bull B has a BW EPD of -5, so we

would expect the average progeny

of Bull B to weigh 6 lbs. less

(-5 - 1 = -6) than the average

progeny of Bull A.

EPDs are calculated using complex statistical models that consider the animal’s pedigree, his or her own

performance, and the performance of related individuals. Two advantages

of EPDs are:

1) Their ability to separate performance due to genetics- versus-environmental factors, and

2) EPDs account for the genetics of both parents in the mating. Due to the combination of these advantages, the resulting EPDs are more complex and more accurate than actual or adjusted weights or ratios, which do not account for environmental influences or the genetics of both sire and dam.