Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 11/16/2007
Publication Date: 9/22/2008
Publication URL: http://asas.org/abstracts/2008sectional/Supplement_3-38.pdf
Citation: Holl, J.W., Rohrer, G.A., Shackelford, S.D., Wheeler, T.L., Koohmaraie, M. 2008. Genetic parameters for kyphosis in pork carcasses [abstract]. Journal of Animal Science. 86(E-Suppl. 3):48. Abstract #32. Interpretive Summary:
Technical Abstract: Genetic parameters for degree of kyphosis were estimated in pigs from a Duroc-Landrace F2 population (n = 316) and in pigs and sows from a composite population (Line C) composed of Duroc, Large White, and two sources of Landrace (n = 1,552). Live presentation did not indicate kyphosis in pigs or sows. Degree of kyphosis was measured by scoring the shape of the vertebral column of split carcasses on a scale from 0 (normal) to 3 (severe). There were no significant differences in kyphosis between sows and pigs in Line C. Of the animals slaughtered, 75.6% and 68.9% were normal, 11.1% and 23.3% were mild, 11.1% and 6.2% were moderate, and 2.2% and 1.5% were severe in F2 and Line C, respectively. Using linear models, fixed effects of age, sex, number of ribs, number of lumbar vertebrae, number of nipples, carcass length, and hot carcass weight, were not significantly associated (P > 0.10) with kyphosis score. Using an animal model, estimated heritabilities for kyphosis score were 0.30 and 0.32 in F2 and Line C, respectively. Estimated genetic correlations between kyphosis score and number of ribs, number of lumbar vertebrae, number of nipples, carcass length, and hot carcass weight were 0.05, -0.13, 0.00, 0.05, and 0.03, respectively. Estimated phenotypic correlations between kyphosis score and number of ribs, number of lumbar vertebrae, number of nipples, carcass length, and hot carcass weight were 0.03, -0.05, -0.05, 0.05, and 0.01, respectively. Selection to decrease kyphosis should be effective and not affect the number of ribs, lumbar vertebrae, nipples, or carcass length. In addition, selection for growth should not affect the genetic potential for incidence of kyphosis.