Bovine Respiratory Disease in Feedlot Cattle: Phenotypic, Environmental, and Genetic Correlations with Growth, Carcass, and Palatability Traits

Authors: Snowder, Gary; Van Vleck, Lloyd; Cundiff, Larry; Bennett, Gary; Koohmaraie, Mohammad; DIKEMAN, MICHAEL - KANSAS STATE UNIVERSITY

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2007
Publication Date: 7/16/2007
Citation: Snowder, G.D., Van Vleck, L.D., Cundiff, L.V., Bennett, G.L., Koohmaraie, M., Dikeman, M.E. 2007. Bovine respiratory disease in feedlot cattle: Phenotypic, environmental, and genetic correlations with growth, carcass, and palatability traits. Journal of Animal Science. 85:1885-1892.

Interpretive Summary: Bovine respiratory disease, also known as shipping fever, is the most costly feedlot disease in the United States. Selection for disease resistance is one of several possible interventions to prevent or reduce economic loss associated with animal disease and to improve animal welfare. However, undesirable genetic relationships between production and disease resistance traits often exist. The objective of this study was to estimate the phenotypic, environmental, and genetic correlations of bovine respiratory disease with growth, carcass, and palatability traits. These correlations were estimated from a very large data set of health records on 18,112 feedlot cattle over a 15 year period and slaughter data on 1,627 steers over a 4 year period. Traits included average daily gain, adjusted carcass fat thickness at the 12th rib, marbling score, longissimus muscle area, weight of retail cuts, weight of fat trim, bone weight, Warner-Bratzler shear force, tenderness score, and juiciness score. Phenotypic, environmental, and genetic correlations of observed traits with bovine respiratory disease ranged from -0.35 to 0.40, -0.36 to 0.55, and -0.42 to 0.20, respectively. Most correlations with bovine respiratory disease were not important. No correlations of bovine respiratory disease with palatability and average daily gain were of concern. Bone weight as a percentage of carcass weight had a moderate genetic correlation with bovine respiratory disease (-0.42). These low or near zero estimates of genetic correlations infer selection to reduce bovine respiratory disease in feedlot cattle would have negligible correlated responses on growth, carcass, and palatability traits; or that selection for those traits will have little effect on bovine respiratory disease susceptibility or resistance.

Technical Abstract: Bovine respiratory disease (BRD) is the most costly feedlot disease in the United States. Selection for disease resistance is one of several possible interventions to prevent or reduce economic loss associated with animal disease and to improve animal welfare. Undesirable genetic relationships, however, may exist between production and disease resistance traits. The objectives of this study were to estimate the phenotypic, environmental, and genetic correlations of BRD with growth, carcass, and longissimus palatability traits. Health records on 18,112 feedlot cattle over a 15 yr period, and slaughter data on 1,627 steers over a 4-yr period were analyzed with bivariate animal models. Traits included ADG, adjusted carcass fat thickness at the 12th rib, marbling score, longissimus muscle area, weight of retail cuts, weight of fat trim, bone weight, Warner-Bratzler shear force, tenderness score, and juiciness score. The estimated heritability of BRD incidence was 0.08 ± 0.01. Phenotypic, environmental, and genetic correlations of observed traits with BRD ranged from -0.35 to 0.40, -0.36 to 0.55, and -0.42 to 0.20, respectively. Most correlations were low or negligible. Percentage of carcass bone had moderate genetic, phenotypic, and environmental correlations with BRD (-0.42, -0.35, and -0.36, respectively). Hot carcass weight and weight of retail cuts had moderate undesirable correlations with BRD (0.37 and 0.48, 0.40 and 0.55, respectively). Correlations of BRD with longissimus palatability and ADG were not detected. Low or near zero estimates of genetic correlations infer that selection to reduce BRD in feedlot cattle would have negligible correlated responses on growth, carcass, and meat palatability traits; or that selection for those traits will have little effect on BRD susceptibility or resistance.