Zimmermann breed heterotic mature weight cattle

The mature weight of cows at slaughter has increased over the last several decades, making the day-to-day management and feeding costs can also increase. This can affect the efficiency of cattle production, but most studies have demonstrated that the association between cow weight and efficiency is highly dependent on environment. A recent paper by Zimmermann et al., “Breed and heterotic effects for mature weight in beef cattle” assessed the genetics of mature cow weight to help producers improve the efficiency of production with appropriate genetic choices. 

The authors successfully estimated heterosis, the genetic parameters, and breed correlations of mature cow weight using data on cow growth collected at the USDA, ARS U.S. Meat Animal Research Center. Crossbreeding would cause cows to be approximately 15 kgs larger at maturity due to heterosis. Heterosis may also hasten maturation, but additional research needs to be done to assess these effects. The direct heritability of mature cow weight was 0.56, which is similar to previously published heritability in steers. Angus cows were found to be heaviest at maturity of the breeds assessed and Braunveih were the lightest. 

This paper provides valuable information about the heritability of mature cow weight across different cattle breeds. This information can help producers make crossbreeding decisions for their operation, as optimal mature cow size is environment and management dependent.