Heat Stress in Livestock: Welfare and Production Impacts of Rising Temperatures

Climate change is intensifying heat stress in livestock globally. Heat stress causes significant animal suffering and production losses, making mitigation a both welfare and economic priority.

Key Facts

Heat stress occurs when animals cannot dissipate body heat fast enough to maintain thermal equilibrium
Dairy cattle begin experiencing heat stress above 22 degrees C temperature-humidity index (THI)
Heat stress reduces feed intake, milk production, reproduction, and immune function in cattle
Pregnant animals under heat stress produce offspring with lifelong productivity deficits
Poultry are particularly vulnerable to heat stress - broiler chickens show mortality increases above 30 degrees C
Shade provision reduces livestock heat stress significantly but is absent in many intensive systems
Sprinkler systems combined with ventilation fans are the most effective heat abatement for dairy cows
Black globe thermometers measure apparent temperature perceived by animals better than air temperature alone

Welfare Considerations

Heat stress causes genuine physiological and behavioral suffering in livestock. Animals in thermal distress pant, reduce activity, seek shade, cluster near water, and show elevated stress hormone levels. Severe heat stress causes mortality. The chronic effects - reduced immunity, poor reproduction, offspring development impacts - compound the acute suffering into long-term welfare consequences for individual animals and their descendants. As climate change intensifies heat events, livestock welfare is increasingly threatened in regions that previously experienced manageable summer conditions. Welfare-positive responses include providing shade, cooling systems, and adjusting management practices around peak heat periods. These are also economically motivated responses, creating alignment between welfare and production goals.

What You Can Do

Support livestock farms that provide shade structures, water access, and cooling systems in hot conditions
Advocate for heat stress mitigation requirements in farm animal welfare standards
Choose products from farms with documented heat stress management protocols
Support climate policy that reduces greenhouse gas emissions causing intensification of heat events
Engage with farm assurance bodies to include heat stress monitoring and mitigation in their standards
Learn about heat stress indicators in different species to better evaluate farm welfare claims