Livestock

Cattle Heat Stress 2025: Climate Change and Welfare

2025 welfare update on heat stress in cattle -- climate change implications and management responses.

Key Facts

Heat stress in dairy cows causes reduced feed intake, reduced milk production, and increased disease risk
The temperature-humidity index (THI) above 68 indicates heat stress risk -- above 82 is severe stress
UK dairy cows are increasingly exposed to heat stress as summer temperatures rise with climate change
2025 research confirms that even mild heat stress causes significant production and welfare impacts
Cooling interventions including fans, evaporative cooling, and shade provision reduce heat stress significantly
Water intake increases dramatically during heat stress -- adequate trough space and clean water are welfare essentials
Reproductive performance is severely affected by heat stress -- embryo death increases in hot weather
Building design and ventilation retrofitting for heat stress is increasingly justified economically and welfare-wise

Welfare Significance

Heat stress in cattle is a welfare impact of climate change that is already affecting UK dairy farms. As summers become warmer and more frequent heatwaves occur, the welfare burden of heat stress will grow. Proactive investment in cooling infrastructure, building ventilation, and shade provision protects current welfare and is increasingly financially justified as climate trends continue.

What You Can Do

Monitor temperature-humidity index in housed cattle during summer and have cooling ready to activate
Ensure adequate clean water access -- cows under heat stress may need double normal water intake
Retrofit building ventilation with fans or evaporative cooling where economically feasible
Consult a specialist about building design for heat stress mitigation as part of any new construction or renovation