Do birds spread harmful bacteria on dairy farms?

Andrea Ayala, assistant professor of natural resources and the environment, is studying  the role small birds play in transmitting Campylobacter jejuni — a bacterium that can affect herd health and cause foodborne illness in humans — to cows at dairy farms in New Hampshire and across the U.S. Early observations indicate that house sparrows likely play a much larger role in the spread of Campylobacter and other bacteria harmful to animal health than previously thought.

Dairy cows are known to carry Campylobacter, though not at levels that pose a health threat. But sparrows can carry additional Campylobacter populations that tip the balance toward infection.

If confirmed, the findings would reinforce the value of vaccinating cows against Campylobacter infection and installing netting to keep the birds away from barns and feed storage areas.

“If we can show clearly that sparrows are initiating Campylobacter infections in cows, it demonstrates to farmers that mitigation strategies are well worth it,” says Ayala.

There are more than 20 species of Campylobacter, but Ayala is focused on C. jejuni because of its impact on human, animal, and environmental health.   

The research is funded by the NH Agricultural Experiment Station.