USDA Grant Supports MSU Research Into Dairy Cattle Heat Stress

By Erin Buckley

Mississippi State scientists are studying new ways to mitigate heat stress in dairy cattle—a national problem costing the industry approximately $1.5 billion in lost production—thanks to a $300,000 New Investigator Seed Grant from the USDA’s National Institute of Food and Agriculture.

The MSU Mississippi Agricultural and Forestry Experiment Station’s Joe Bearden Dairy Research Center, College of Veterinary Medicine and Institute for Genomics, Biocomputing and Biotechnology are collaborating on a two-year study unraveling the crosstalk between rumen microbiota and the enteric and central nervous systems in dairy cattle under heat stress. This improved understanding will help researchers develop innovative mitigation strategies targeting this rumen-brain-microbiome axis that can be shared with producers.

Leading the team is Peixin Fan, an assistant professor in MSU’s Department of Animal and Dairy Sciences, along with ADS faculty members and MAFES researchers Caleb Lemley, Derris Devost-Burnett and Rhonda Vann.

“Dairy cows sweat less efficiently compared to humans but generate more heat during lactation, so keeping them comfortable during high-heat events is necessary, particularly in the southern region of the U.S. with the hot and humid climate,” Fan said. “Heat stress reduces appetite and affects rumen fermentation, both of which are closely linked to the loss of milk yield. In addition to extracting nutrients from feed and providing energy to animal hosts, certain gastrointestinal microbes can produce neuroactive compounds and have potential to affect animal behavior.”

Better understanding of how heat affects cows is expected to unlock innovative strategies for improving animal resilience, a vital need for Southeastern dairies, Lemley said.

“Producers can utilize cooling strategies, such as sprinklers and fans, to improve cow performance,” he said. “Our understanding of the relationship between heat stress and gut microbial communities, however, is severely limited, which is what Dr. Fan’s novel research aims to address.”