Livestock Welfare

Heat Stress in Poultry: Welfare in a Warming Climate

Managing heat stress in poultry — an increasingly critical welfare challenge as temperatures rise.

Key Facts

Poultry are highly susceptible to heat stress — their upper thermal comfort limit is approximately 24-27 C
Heat stress causes reduced feed intake, increased water consumption, respiratory alkalosis, and death
Broilers, particularly fast-growing breeds, are especially vulnerable due to high metabolic heat production
Climate change is making extreme heat events more frequent, intensifying welfare risks
Adequate ventilation, shade, and cool water are the primary mitigation strategies

Welfare Considerations

Heat stress causes significant acute and chronic welfare impairment in poultry. As ambient temperature rises above the thermal comfort zone, birds attempt to dissipate heat through panting (evaporative cooling). Respiratory alkalosis from prolonged panting causes blood pH changes that impair multiple physiological systems. Feed intake drops, growth slows, egg production falls, and immune function is suppressed.

Severe heat stress causes death — particularly in broiler houses without adequate ventilation or during power failures that disable ventilation systems. Mass mortality events from heat stress occur regularly during extreme weather. The suffering during heat stress death — hyperthermia, respiratory distress, weakness, and collapse — is significant.

Effective heat stress mitigation requires adequate ventilation capacity designed for extreme weather scenarios, evaporative cooling systems, provision of cool, clean water at all times, reduced stocking density during heat events, and feed modification (increased electrolytes, reduced heat-generating metabolism). Emergency protocols for power failures are essential.

What You Can Do

Ensure poultry housing has adequate ventilation capacity for extreme weather events
Install evaporative cooling systems in high-risk regions or for intensive operations
Maintain cool, clean water availability at all times — water intake doubles in heat
Have emergency power backup protocols for ventilation systems
Reduce stocking density and adjust feed composition during anticipated heat events