34 NEBRASKA CATTLEMAN January 2026 Sire Selection Steps MATT SPANGLER, PH.D. | RONNIE D. GREEN PROFESSOR OF ANIMAL SCIENCE AND EXTENSION BEEF GENETICS SPECIALIST, DEPARTMENT OF ANIMAL SCIENCE, UNIVERSITY OF NEBRASKA-LINCOLN Expected progeny differences (EPDs) have been around for close to 50 years, so it is nearly impossible for any reader to have avoided hearing about them at some point. Yet, survey results conducted by both academics and popular press publications suggest that EPDs do not serve as the primary selection criterion used by commercial producers. This is a critical failure on multiple fronts and begs the question: If a known and validated tool is to be ignored, can the U.S. beef industry reasonably argue that it is on the path toward sustainability? SETTING GOALS I suspect that nearly everyone sets goals, if even informally. In the field of animal breeding and genetics this exercise is called “developing a breeding objective.” At a high level, a breeding objective identifies a few fundamental plans, including how replacement females will be obtained, when calves will be sold and how calves will be sold. From simply developing plans that answer these three questions, producers can identify a list of traits that are economically relevant to their breeding objective. Economically relevant traits (ERTs) are those that are directly tied to a source of revenue or a source of cost. For example, weaning weight would be economically relevant for someone who sells calves at weaning, given their revenue is related to the weight of calves when they sell them. Similarly, carcass weight would be an ERT for someone who retains ownership and sells cattle on a grid. For someone who purchases replacement females, maternal traits are not important when selecting bulls. However, if replacement females will be kept, then traits like mature cow weight, maternal weaning weight (milk) and stayability (sustained cow fertility, functional longevity) become important. Breeding objectives can be layered with additional detail once the high-level plans are known. This additional detail could include current levels of performance of the cow herd and calves produced. For example, if a producer knows that their cattle grade Low Choice (on average), then there is economic incentive to increase marbling score to improve quality grade. If the same producer has a 0 percent incidence of dystocia in heifers, then there is little economic incentive to continually select for improved calving ease. Finally, constraints on the system – such as availability of labor, land and/ or forage – can be identified as a means of determining how an individual enterprise’s costs might differ from that of other entities. Breeding objectives can vary from those that are exceptionally detailed to those that simply state core objecPRODUCTION
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