Basics of EPD

Many traits (weaning weight, yearling weight, ultrasound measurements, etc.) must be recorded within certain age windows (ranges when it is acceptable to measure animals). Animals measured outside of defined age windows will not have their own record incorporated into an EPD calculation. This allows for a fair comparison of animals. Specific age windows can be found on the corresponding breed association website.

Too often seedstock producers and bull buyers get caught up in the actual weights, ultrasound data, etc., when selecting sires. EPDs provide a measure by which animals within a breed can be compared to one another for their genetic potential as parents for specific traits. EPDs incorporate multiple sources of information, including full pedigree, an animal’s own record, and progeny information. As additional sources of information become available, the accuracy of the EPD value increases. Prior to a National Cattle Evaluation (NCE), animals are given interim EPDs. During a genetic evaluation, all pedigree information would be included.