Practical applications of genomics

Abstract

Genomic testing serves multiple functions for beef cattle popu­lations. Since their inception in the late 2000s, genomic tests have been critical tools for detecting mutations that cause genetic defects, parentage testing, and improving the quality of genetic predictions. Sire selection is one of the most conse­quential decisions that commercial operations make. This chal­lenge is compounded by the relatively low levels of information available on the unproven herd sires that commercial herds purchase. Selection tools in the form of Expected Progeny Dif­ferences (EPDs) allow commercial operations to reduce the risk involved in sire selection. EPDs isolate the genetic component of economically-relevant traits and increase selection accuracy. While parent average EPDs are more reliable than phenotypic selection, unproven sires can still experience significant EPD shifts as more information becomes available. Genomic testing enhances the EPDs for unproven and low-accuracy sires. These increases in accuracy are equivalent to approximately a calf crop’s worth of records in a genomic evaluation (from 10 to 30 phenotypes depending on the trait). Nearly all breed associa­tions calculate genomically-enhanced EPDs, making their use imperative for commercial operations. Beyond bull selection, opportunities exist for commercial producers to utilize genom­ics for heifer selection and marketing terminal animals.