Livestock Heat Stress: Climate Change and Farm Animal Welfare

Heat stress causes significant welfare problems in livestock and will worsen with climate change. Understanding mitigation strategies helps protect animals in warming conditions.

Key Facts

Heat stress occurs when animals cannot dissipate heat fast enough to maintain normal body temperature
Dairy cows begin heat stress at 22 degrees Celsius; pigs at 25 degrees; poultry at 25-30 degrees
Signs include increased respiration, reduced feed intake, seeking shade, and standing in water
Severe heat stress causes deaths — UK heatwaves have caused significant poultry and pig mortality
Shade, ventilation, cool water, and scheduling activity during cooler periods are primary interventions
Evaporative cooling systems can reduce effective temperature in housed animals significantly
Climate change will extend the duration and intensity of heat stress events across most livestock regions

Welfare Considerations

Livestock heat stress is an increasingly serious welfare challenge as climate change makes extreme heat events more frequent and intense. The welfare impacts of heat stress range from subclinical discomfort and reduced performance to acute suffering and death in extreme events. Pigs are particularly vulnerable — they cannot sweat effectively and have limited behavioural thermoregulation options in intensive housing. Poultry in intensive housing with inadequate ventilation can experience rapid mass mortality during heat waves. Dairy cows in heat stress show reduced lying times, altered social behaviour, and dramatically reduced milk production. Proactive climate adaptation in livestock farming — including improved housing ventilation, shade provision, and cooling systems — is both a welfare and a business imperative in a warming world.

What You Can Do

Support farms that have invested in heat management infrastructure including shade and ventilation
Advocate for climate-appropriate minimum temperature standards in livestock housing regulations
Choose animal products from farms with certified welfare standards that include heat stress management
Support climate action policies that reduce the warming driving more frequent heat extremes
Donate to livestock welfare organisations working on climate adaptation strategies for farming