How might genomic information get translated into industry outcomes?

Abstract Text: The five-year USDA-funded Bovine Respiratory Disease Complex Coordinated Agricultural Project (BRD CAP; USDA-AFRI 2011-68004-30367) aims to develop genetic markers associated with bovine respiratory disease (BRD) to enable the genetic identification of cattle that are less susceptible to BRD. Ultimately the aim of this project is to integrate predictive markers for BRD susceptibility into genetic tests and national cattle genetic evaluations. The research team is activity working to identify regions of the genome associated with BRD susceptibility in both dairy and beef cattle. Initial results have identified multiple genomic regions that were significantly associated with BRD susceptibility. Genomic selection has been introduced into dairy cattle breeding programs globally and within breed genomic estimated breeding values (GEBV) are published in a number of countries. Work is ongoing to integrate BRD information into dairy cattle evaluations at the appropriate economic weighting. However the incorporation of genomic information into beef cattle evaluations has been more problematic due to the presence of numerous breeds and the importance of crossbreeding in the commercial cattle population. Linkage disequilibrium between markers and quantitative trait loci (QTL) is not consistent across breeds, and so markers that were identified in one breed were frequently uninformative in other breeds. However, the sequencing of a large number of animals has opened up the possibility of identifying the actual SNP variations that are causing genetic variation.  It is envisioned that by imputing the genotypes of reference animals collected by the BRD CAP up to full sequence and further fine mapping and analyses, the causative genetic variants associated with BRD susceptibility will be identified, and that inclusion of these markers on genotyping platforms will provide a reliable selection criterion to enable for the selection of both beef and dairy cattle that are less susceptible to BRD. There are several advantages associated with using causative SNP makers in selection panels including persistence of the marker effect across generations, and an increased likelihood that causative polymorphisms will be similarly associated with variation across multiple breeds. Ultimately, prospective marker panels will need to be tested in independent cattle populations to ensure they are predictive of BRD phenotype. Towards this end the BRD CAP is working in collaboration both breed associations and commercial feedlots to develop populations of BRD phenotyped animals. Ultimately selection against BRD susceptibility will depend on breeder inclusion of this disease trait in their breeding objective and selection decisions. See http://www.brdcomplex.org for more information.

Keywords: cattle, respiratory disease, extension