The potential value of DNA-based tests for host bovine respiratory disease resistance to the beef cattle industry

Abstract

Recent developments in molecular genetics and genotyping platforms offer a unique opportunity to use modern genomic tools to manage the future health of beef cattle. Reducing the considerable animal morbidity, mortality, and economic losses associated with bovine respiratory disease (BRD) will require the simultaneous development of DNA tests to enable the selection of resistant animals, and the incorporation of this trait into breeding objectives of relevance to US beef production systems. This study focused on determining the relative weighting that should be given to selection for BRD resistance in a multi-trait selection index for Angus terminal sires. All herd-level economic statistics were modeled for a 1000 cow-calf enterprise, and retained ownership through the feedlot was assumed. All progeny of terminal sires were harvested, and so no economic value was associated with maternal traits. Reducing BRD incidence was the trait that was associated with the highest relative economic value. To maximize profitability for the operation, it was determined that reducing BRD incidence should be weighted approximately seven times more heavily in a terminal sire selection index than weaning weight, postweaning average daily gain and feed intake, and that these traits should receive two to three times more emphasis than marbling score and yield grade. To incentivize the inclusion of genomic BRD susceptibility criteria in breeding decisions, and to offset the concomitant decreased selection pressure on growth traits that return value directly to producers who do not retain ownership (i.e. sell on a weight basis prior to feeding), there would need to be some mechanism analogous to a backgrounding premium to transfer the savings from improved feedlot health back up the supply chain to producers and breeders.