|Matukumalli, Lakshmi -|
Submitted to: Animal Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 14, 2010
Publication Date: June 14, 2010
Citation: Garcia, M.D., Matukumalli, L., Wheeler, T.L., Shackelford, S.D., Smith, T.P., Casas, E. 2010. Markers on bovine chromosome 20 associated with carcass quality and composition traits and incidence of contracting infectious bovine keratoconjunctivitis. Animal Biotechnology. 21(3):188-202. Interpretive Summary: The beef production system in the United States is designed to produce high-quality beef. Disease prevalence is a factor affecting productivity in the beef industry. It is essential to establish if the relationship between becoming affected by disease and productivity is genetically associated. The objective of the present study was to evaluate the association of genetic markers with prevalence of pinkeye and carcass composition traits. This initial study suggests the possibility that genes that affect the ability to cope with disease, are also involved in the performance of the animal on productive and carcass traits.
Technical Abstract: The objective of this study was to use single nucleotide polymorphisms (SNP) on bovine chromosome 20 to fine map a previously identified QTL associated with the incidence of infectious bovine keratoconjunctivitis (IBK). Crossbred steers (GPE7; n = 539) derived from sires of 7 Bos Taurus breeds 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 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 traits to identify possible antagonistic effects of possible 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 indicates that this QTL region is an area of interest for further marker development.