Farm Animals

Heat Stress in Dairy Cattle: Welfare and Productivity

Heat stress affects dairy cattle globally, reducing milk production, reproductive success, and welfare in ways that climate change is intensifying.

Key Facts

Dairy cows become heat stressed above 25 degrees Celsius in high humidity
Heat-stressed cows produce 10-25% less milk and have lower conception rates
Shade, fans, and sprinklers are highly effective at reducing heat stress
Black and white Holstein cows absorb more solar radiation than lighter breeds
Heat stress during late pregnancy impairs calf immune development

Welfare Considerations

Heat-stressed cows pant, seek shade, reduce feed intake, and cluster at water sources. Chronic heat stress suppresses immune function, increases mastitis susceptibility, and causes metabolic disorders. Cows on pasture have natural behavioral options including shade-seeking, but intensively housed cows depend entirely on their facilities for relief. Adequate cooling infrastructure is an essential welfare requirement, not a luxury, in warm climates.

What You Can Do

Support welfare standards that require cooling infrastructure in warm climates
Advocate for housing design standards that include shade and ventilation
Choose dairy products from farms with transparent welfare standards
Support research into heat-tolerant dairy breeds for climate adaptation