Livestock in Heat Waves: Climate and Welfare

Increasing frequency of heat waves threatens the welfare of billions of farm animals worldwide, with cattle, pigs and poultry all showing severe heat stress responses during extreme temperatures.

Key Facts

Heat stress costs the US livestock industry over 2 billion dollars annually through reduced production and mortality
Dairy cows begin showing heat stress at 22C, experiencing reduced milk production, fertility and immune function
Pigs are particularly vulnerable to heat stress as they cannot sweat and have limited thermoregulation ability
Broiler chickens in crowded houses without cooling can experience mass mortality events during heat waves
Climate change is projected to increase the frequency of extreme heat events in major livestock-producing regions

Welfare Considerations

Heat stress in farm animals is a welfare problem that will intensify with climate change. Animals in intensive production systems are particularly vulnerable because high stocking densities, metabolic heat from rapid growth or high milk production, and buildings designed for cooler climates create conditions in which extreme temperatures become deadly. The suffering of heat stress is acute — it involves respiratory distress, disorientation, cardiovascular strain and eventually death. Transitioning to lower-stocking-density housing with better ventilation, shade access for outdoor animals, and production systems less dependent on high-metabolic breeds would reduce heat stress vulnerability.

What You Can Do

Support farms investing in heat stress management infrastructure including cooling systems and shade
Advocate for heat stress contingency planning to be required in all livestock farm welfare plans
Choose products from farms with documented heat management protocols
Support climate policies that reduce future heat wave frequency and intensity