Broiler Heat Stress: Welfare and Production Impacts

Heat stress is a growing welfare problem for fast-growing broiler chickens, particularly as climate change increases summer temperatures in production regions worldwide.

Key Facts

Broiler chickens lack functional sweat glands and rely on panting to cool down
Modern fast-growing breeds have high metabolic rates generating excess body heat
Heat stress above 25-30C causes panting, lethargy, reduced feed intake and death
Mortality events during heat waves can kill thousands of birds in hours
Slower-growing breeds are more heat-tolerant due to lower metabolic rates
Shade, ventilation, cool water and misting systems all reduce heat stress

Welfare Considerations

Heat stress in broilers is a serious welfare issue causing acute suffering - birds panting desperately, wings held away from the body, collapsing and dying. The problem is compounded by the biology of fast-growing breeds whose metabolism generates so much heat they struggle even in mild conditions. As climate change intensifies heat waves, heat stress mortality events are projected to increase substantially. The transition to slower-growing breeds addresses heat tolerance alongside other welfare improvements, while better housing ventilation provides mitigation.

What You Can Do

Support Better Chicken Commitment certifications requiring slower-growing breeds
Advocate for mandatory ventilation standards in poultry housing
Choose chicken products with higher welfare certifications
Support climate adaptation research for poultry housing systems