Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 2, 2006
Publication Date: December 2, 2006
Citation: Casas, E., Stone, R.T. 2006. Putative quantitative trait loci associated with the probability of contracting infectious bovine keratoconjunctivitis. Journal of Animal Science. 84:3180-3184. Interpretive Summary: As part of a larger study to detect the location of genes associated with economically important traits in cattle, the objective of the present study was to identify the location of genes influenced by infectious bovine keratoconjunctivitis. This condition in cattle is also known as “pinkeye”. The annual estimated economic loss due to the disease is approximately $150 million. The main pathogen responsible for the disease is Moraxella bovis. Regions on bovine chromosomes 1 and 20 were identified as harboring genes affected by the presence of the bacteria. Further studies are necessary to identify the genes responsible for the observed effect.
Technical Abstract: Infectious bovine keratoconjunctivitis, also known as pinkeye, is an economically important disease in cattle. The objective of this study was to detect quantitative trait loci associated with infectious bovine keratoconjunctivitis in offspring from a Brahman x Hereford sire. The sire was mated to Hereford, Angus and F1 cows to produce 288 offspring in 1994, and mated to MARC III (¼ Hereford, ¼ Angus, ¼ Red Poll, and ¼ Pinzgauer) cows in 1996 to produce 259 offspring (547 animals total). Infectious bovine keratoconjunctivitis was diagnosed by physical examination in 36 animals of the family. Records included unilateral and bilateral frequency, but not severity. Records were binary; “zero” for unaffected and “one” for affected cattle. A putative quantitative trait loci for infectious bovine keratoconjunctivitis was identified on chromosome 1, with a maximum F-statistic (F = 10.15; P = 0.0015) at centimorgan 79 of the linkage group. The support interval spanned centimorgans 66 to 110. There was also evidence suggesting the presence of a quantitative trait loci for infectious bovine keratoconjunctivitis on chromosome 20, with a maximum F-statistic = 10.35 (P = 0.0014) at centimorgan 16 of the linkage group. The support interval ranged from centimorgan 2 to centimorgan 35. No clear candidate gene can be identified as responsible for infectious bovine keratoconjunctivitis on these chromosomes.