Modern beef production increasingly rewards animals that grow at a consistent and predictable rate. In this study, we evaluated whether growth variability in American Angus cattle has a genetic component and whether it could be considered in breeding programs. Using growth records from nearly 75,000 American Angus cattle, we investigated birth weight, weaning weight, and yearling weight. Our results showed that residual variance had a genetic component, although heritability estimates for residual variance were low. The results suggest that reducing variability through selection may be feasible, but progress is expected to be gradual. For birth weight, uniformity should be considered carefully because the breeding goal is generally to maintain birth weight within an optimal range to avoid calving difficulty. For weaning and yearling weights, selection for higher average growth may increase variability unless uniformity is included in selection decisions. Overall, this study provides an initial step toward evaluating growth uniformity as a potential component of future beef cattle breeding objectives.

Read the full article in the Journal of Animal Science.