Interpretive Summary: Genetic parameters, heterosis, and breed effects for body condition score and mature cow weight in beef cattle

By: André Mauric F. Ribeiro, Leticia P. Sanglard, Larry A. Kuehn, Warren M. Snelling, R. Mark Thallman, and Matthew L. Spangler

The current study estimated the genetic relationship between mature cow weight (MWT) and body condition score (BCS), heterosis, and breed effects for these traits in a crossbred beef population. In total, 25,035 and 24,522 overlapping records were available for MWT and BCS, respectively. Pedigree was available for 48,013 individuals. Heritability and genetic correlations were estimated within a trait between parities, between traits within parities, and between traits across parities. Estimates of heritability ranged from 0.40 ± 0.02 to 0.55 ± 0.07 for MWT and from 0.11 ± 0.01 to 0.25 ± 0.04 for BCS. Genetic correlations within a trait and between parities were, in general, high. Estimates of genetic correlation between MWT and BCS were positive and moderate, ranging from 0.32 ± 0.09 to 0.68 ± 0.14. Heterosis effects were 21.56 ± 3.53 kg for MWT and 0.095 ± 0.034 for BCS. For both traits, Brahman and Braunvieh were associated with the highest and lowest breed effects, respectively. These results suggest that MWT and BCS would respond favorably to selection and are moderately genetically correlated. Breed differences and heterotic effects could be used to parameterize multibreed genetic evaluations for indicators of cow maintenance energy requirements.

Read the full article on the Journal of Animal Science.