Use of Heifer Pregnancy EPDs

Heifer pregnancy EPDs are to be used as a tool to increase the chance of a sire's daughters becoming pregnant during a normal breeding season. The unit of measure for the EPD is a percentage. A higher EPD is the more favorable direction for selection pressure. As with other EPDs, the relative difference among sires is of importance rather than the absolute value.

Figure 1 provides an example of the use of heifer pregnancy EPDs. Assume there are 100 daughters for each of the two bulls, managed and treated alike in the same breeding environment. When comparing the two bulls, one would expect an average of 5 more pregnant daughters out of 100 from Bull A compared with Bull B. Essentially Bull A's daughters have a 5% greater chance of becoming pregnant than Bull B's daughters.