When late-gestation cows suffer heat stress, their calves pay the price, too. That’s the conclusion of a recently published University of Florida study.

The study, summarized by Penn State University research associate Colleen Jones, concludes that calves exposed to heat stress before birth have lower birth weights and compromised immunity. Specifics of the study include:

  • A total of 34 Holstein dry cows in their last 45 days of gestation were evaluated. Half were exposed to ambient environmental conditions, and half were provided with cooling from fans and sprinklers.
  • Calves born to the heat-stressed dams weighed 13 pounds less at birth and 28 pounds less at weaning than those born to dams with access to cooling.
  • Calves born to heat-stressed dams were less efficient at absorbing IgG from colostrum and had lower serum IgG concentrations for the first 28 days of life.
  • Cell-mediated immunity also was negatively impacted in the calves born to heat-stressed dams.

You can read a more comprehensive summary of the study here.


Source: Penn State Extension Dairy News, by Colleen Jones, Research Associate