In the above example, assume that the two bulls were each mated to the same set of cows. Bull B. It is important to recognize that EPDs predict the expected difference in performance, not the actual performance. In other words, the EPDs for Bulls A and B suggest there will be 4 pounds difference in birth weight in their progeny when we mate them comparably. EPDs do not predict what the actual birth weight of the calves will be. Generally, bulls that are below breed average for birth weight EPD should be selected for use on heifers.
Birth weight has a positive relationship with growth rate.
Therefore, most sires that have below average birth weight EPDs will also have below average weaning weight and yearling weight EPDs. However, there are sires available that are below average for birth weight and excel breed average for growth traits. This is an important consideration, as acceptable growth rate does not need to be sacrificed at the expense of getting a live calf born. Producers should consider setting maximum standards for birth weight EPD along with minimum standards for growth EPDs when selecting bulls. Breed average EPDs for bulls born in 1997 are presented in the following table.