Plant & Animal Genomes XVIII Conference

January 9-13, 2010
Town & Country Convention Center
San Diego, CA

Markers On Bovine Chromosome 20 Associated With Carcass Quality And Composition Traits And Incidence Of Contracting Infectious Bovine Kerotoconjunctivitus

Matthew, D. Garcia , Lakshmi Matukumalli , Tommy L. Wheeler , Stephen D. Shackelford , Tim, P.L. Smith , Eduardo Casas

  Louisiana State University 105 Francioni Hall Baton Rouge, LA 70803

M. D. Garcia1,3, L. Matukumalli2, T. L. Wheeler1, S. D. Shackelford1, T. P. L. Smith1, E. Casas1
1USDA, ARS, U.S. Meat Animal Research Center, USDA, ARS, Clay Center NE 68933
2Beltsville Animal Research Center, Bovine Functional Genomics Laboratory USDA
3Loisiana State University, Department of Animal Sciences, Baton Rouge, LA 70803
Abstract
The objective of this study was to evaluate single nucleotide polymorphisms (SNP) on bovine chromosome 20 to fine map a previously identified QTL associated with the incidence of infectious bovine keratoconjunctivitus (IBK). Crossbred steers (GPE7; n = 539) derived from sires of 7 Bos taurus breeds comprising Cycle 7 of the Germplasm Evaluation project, and having veterinary records related to IBK were used to test association of a total of 105 SNP located under the most relevant region of the QTL. Five SNP showed an association with IBK (P<0.05), as animals inheriting differing genotypes from individual SNP exhibited significantly different incidence rates of IBK. The population also had numerous other phenotypes, supporting evaluation of association of the 105 markers with carcass quality and yield traits to identify possible antagonistic effects of possibly utilizing marker-assisted selection for IBK susceptibility. An association of 2 SNP for marbling and tenderness was identified, along with 3 SNP associated with the percentage of carcasses classified as choice. Four SNP were associated with fat yield, 2 SNP with longissimus muscle area and 2 additional SNP with dressing percentage. Although multiple SNP were associated with both IBK and carcass traits, the association of these markers only indicates that this QTL region is an area of interest for further marker development. Further genotyping of markers in this region is necessary to fully evaluate the usefulness of markers in this QTL region for potential marker assisted selection programs.
Key words: beef cattle, carcass traits, health, pinkeye, selection