Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: February 14, 2007
Publication Date: February 14, 2007
Citation: Sonstegard, T.S., Matukumalli, L.K., Gasbarre, L.C., Silva, M.V., Van Tassell, C.P. 2007. Applied bovine genomics: New opportunities for managing disease and intensifying production. [abstract]. Meeting Proceedings.
The sequencing of the bovine genome has resulted in the development of experimental tools and reagents that will greatly enhance genome biology research in cattle, especially for traits affecting health. Previously, mapping studies to identify quantitative trait loci (QTL) affecting health traits were limited by the phenotypes that could be extracted from experimental populations optimized for QTL mapping (i.e. F2 and backcross populations). Results from these studies have not always been readily applicable for enhancing genetic improvement in commercial populations. However, some of these limitations can be overcome with the availability of dense single nucleotide polymorphism based genotyping assays. These mapping tools allow determination of linkage disequilibrium for disease traits across populations, or alternatively, the improvement of multiple traits based on genome composition. We are investigating the feasibility of both approaches by performing a genome-wide association study in both the U.S. commercial dairy population across all nationally recorded traits and on an experimental cattle population previously found to contain eight QTL for parasite resistance/susceptibility. The goals of these studies will be to implement genome-wide selection based on haplotype and linkage disequilibrium information and develop a subset of markers denoting important haplotypes for disease susceptibility diagnostics. The application of genome selection should reduce the cost of progeny testing of dairy sires and improve the introgression of disease resistance haplotypes into high production breeds of cattle that allow intensification of production in suboptimal environments. Moreover, these studies will provide new biological information on fertility, mastitis, and parasite resistance/susceptibility. Beyond affecting livestock health, the latter two traits also have potential impact on human health due to the introduction of antibiotics and other drug residues into the food chain.