Genetic testing in beef practice

Abstract

Genomic technologies are emerging as an important tool in beef genetic improvement strategies. Genetic tests are used extensively by many progressive seedstock breeders to increase accuracy of selection and accelerate genetic progress. Increasing use of these technologies in the seedstock sector have also led to development of applications for commercial cattle. There are several keys to technical evaluation of genomic technologies. The first is the accuracy of the prediction which can be expressed as a genetic correlation or an increase in accuracy of EPDs when incorporated into genetic evaluation. The second is the association between the prediction and the observed phenotype. In the case of the genomically enhanced EPD, this is implicit in the reported accuracy. For commercial applications, this should include some external validation of the predictions in a population independent of that used for the development of the test. Provided these validation criteria are met, the application of the technology is very straightforward and effectively the same as historical practices. The principal differences are that the selection decisions can be made earlier in life with greater accuracy, including for traits that are not expressed phenotypically until much later in life. This accelerates genetic progress by minimizing selection mistakes and allowing producers to identify and exploit superior genetics much sooner than with traditional approaches.