Submitted to: World Congress of Genetics Applied in Livestock Production
Publication Type: Proceedings
Publication Acceptance Date: 5/9/2010
Publication Date: 8/1/2010
Citation: Snelling, W.M., Rolfe, K.M., Nielsen, M.K., Freetly, H.C., Ferrell, C.L., Jenkins, T.G. 2010. Genetic and phenotypic parameter estimates for feed intake and other traits in growing beef cattle. Proceedings, 9th World Congress on Genetics Applied to Livestock Production, Leipzig, Germany. August 1-6, 2010. CD-ROM Communication 0285. Interpretive Summary: Feed intake, weight, and flight speed of 1165 crossbred steers were measured during the feedlot finishing period prior to harvest. Flight speed is a proposed indicator of temperament, measured as cattle exited the working chute. Heritability and effects of breed and heterosis on feed intake and feed efficiency, weight and rate of gain, and flight speed records were estimated. Level of heritability and amount of variation indicated that selection for or against feed intake and efficiency measures would be successful. Care would need to be taken to not hurt production or output while aiming to reduce feed intake. Flight speed would not be recommended as an indicator trait for selection to change feed intake or efficiency.
Technical Abstract: Genetic parameters for dry matter intake (DMI), residual feed intake (RFI), average daily gain (ADG), mid-period body weight (MBW), gain to feed ratio (G:F) and flight speed (FS) were estimated using 1165 steers from a mixed-breed population using restricted maximum likelihood methodology applied to univariate and multivariate animal models. Heritability estimates were 0.40 ± 0.02, 0.52 ± 0.14, 0.26 ± 0.10, 0.35 ± 0.12, 0.27 ± 0.10, and 0.34 ± 0.11 for DMI, RFI, ADG, MBW, G:F, and FS, respectively. Although no phenotypic correlation, some genetic correlation still existed between RFI and ADG (-0.15) but little remained between RFI and MBW (-0.02). DMI was highly correlated with RFI (rg = 0.66 and rp = 0.61). Conversely, G:F was correlated with component trait ADG (rg = 0.31 and rp = 0.51). A limited number of significant breed effects was detected between the seven breeds contributing to the population. No evidence of heterosis was detected. FS was not highly correlated to measures of feed intake and efficiency.