Using Breed Composition, Breed Differences, Selection Tools, and New Technologies to Optimize Commercial Cattle Production and Allocation of Beef Cattle in Research Programs.

Indicators of breed composition such as hair color and ear length often result in increased or decreased prices of young calves marketed into feedlots. Similarly, feedlot research trials are often initiated with blended cattle from multiple sources with little more than coat color used as a blocking factor or as an indication of homogeneity. While it is understandable that buyers want to maximize profit by exploiting know breed differences, both applications could be substantially improved with the use of currently available genetic and genomic tools rather than these indicators of breed composition. The objective of this presentation is to detail these technologies and offer suggestions for their use in commercial calf management programs and in research trials. Use of high density genotyping platforms have revolutionized national cattle evaluations. These same platforms can be used to determine breed composition of animals using relatively simple statistical techniques and publically available breed allelic frequencies. Knowledge of breed composition can allow commercial producers and researchers to take advantage of known breed differences in feedlot management and in research designs. While individual genotyping for these applications would be cost prohibitive, techniques such as DNA pooling could be utilized with minimal expense. This same technique could be used to further differentiate predicted performance of groups of cattle when cattle are closely related to sires with known genetic merit from genomically-enhanced EPD. Marketing programs have already been established to take advantage of calves with known sires that have high genetic potential for growth, efficiency, and carcass composition. Genomic testing of pooled DNA samples could allow these marketing programs to be extended to groups of calves with unknown sires. Considerations for current and future usage of these techniques will substantially increase decision support for buying and managing calves and for research allocations even when little is known about their origin at the point of sale. The USDA is an equal opportunity provider and employer.