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United States Department of Agriculture

Agricultural Research Service

Title: Estimates of Parameters Between Direct and Maternal Genetic Effects for Weaning Weight and Genetic Effects for Carcass Traits in Crossbred Cattle

Authors
item Splan, Rebecca - VIRGINIA POLYTECHNIC INST
item Cundiff, Larry
item Dikeman, Michael - KANSAS STATE UNIV.
item Van Vleck, Lloyd

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: July 24, 2002
Publication Date: November 1, 2002
Citation: Splan, R.K., Cundiff, L.V., Dikeman, M.E., Van Vleck, L.D. 2002. Estimates of parameters between direct and maternal genetic effects for weaning weight and genetic effects for carcass traits in crossbred cattle. J. Anim. Sci. 80:3107-3111.

Interpretive Summary: Estimates of maternal genetic ability for weaning weight has been included in breed evaluation programs for some time, but its relationship to carcass characteristics have been relatively unknown. If antagonistic genetic correlations exist between maternal ability and carcass traits, then selection for maternal ability may compromise selection response for carcass traits and reduce profitability of beef production. The objective of this study was to estimate correlations among direct and maternal genetic effects for weaning weight and direct genetic effects for carcass and meat traits in beef cattle. Estimates of heritabilities and genetic correlations were obtained from weaning weight records of 23,681 crossbred steers and heifers, and carcass data of 4,094 crossbred steers produced in the Germplasm Evaluation Program at the U.S. Meat Animal Research Center, Clay Center, NE. Direct and maternal heritabilities for weaning weight were 0.14 and 0.19, respectively. The genetic correlation between direct and maternal weaning weight was negative (-0.18). Heritabilities for carcass traits of steers were moderate to large (0.34 to 0.60). Genetic correlations between direct genetic effects for weaning weight and carcass traits were small, except with hot carcass weight (0.70), ribeye area (0.29) and adjusted fat thickness (0.26). Genetic correlations of maternal genetic effects for weaning weight with direct genetic effects for carcass traits were: hot carcass weight (0.61), retail product percentage (-0.33), fat percentage (0.33), ribeye area (0.29), marbling score (0.28), and adjusted fat thickness (0.25). These results indicate that maternal genetic effects for weaning weight may be correlated with genetics for propensity to fatten in steers. Selection for either increased maternal or direct weaning weight would be expected to result in increased carcass weight, ribeye area, and fat thickness, but would not be expected to affect tenderness.

Technical Abstract: Estimates of heritabilities and genetic correlations were obtained from weaning weight records of 23,681 crossbred steers and heifers, and carcass data of 4,094 crossbred steers using REML applied to animal models. Direct and maternal heritabilities for weaning weight were 0.14 and 0.19, respectively. The genetic correlation between direct and maternal weaning weight was negative (-0.18). Heritabilities for carcass traits of steers were moderate to large (0.34 to 0.60). Genetic correlations between direct genetic effects for weaning weight and carcass traits were small, except with hot carcass weight (0.70), ribeye area (0.29) and adjusted fat thickness (0.26). Genetic correlations of maternal genetic effects for weaning weight with direct genetic effects for carcass traits were: hot carcass weight (0.61), retail product percentage (-0.33), fat percentage (0.33), ribeye area (0.29), marbling score (0.28), and adjusted fat thickness (0.25). These results indicate that maternal genetic effects for weaning weight may be correlated with genetics for propensity to fatten in steers. Selection for only direct weaning weight would be expected to increase carcass weight and ribeye area and slightly decrease marbling and retail product percentage. Selection for either increased maternal or direct weaning weight would be expected to result in increased carcass weight, ribeye area, and fat thickness, but would not be expected to affect tenderness.

Last Modified: 10/22/2014
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