Poultry Heat Stress: Welfare Management

Key Welfare Considerations

• Poultry are particularly vulnerable to heat stress due to their inability to sweat and insulating feather coverage.
• Critical temperature thresholds are approximately 27-28°C for broilers and 27°C for laying hens at normal humidity.
• Respiratory rate elevation (panting) is the primary heat dissipation mechanism, causing energy expenditure welfare costs.
• Core body temperature above 42°C causes cellular damage, neural dysfunction, and mortality in poultry.
• Mortality during heat waves causes significant welfare emergencies — 1°C above comfort zone increases death risk.
• Heat stress causes immunosuppression, increasing disease welfare burden during and after heat events.
• Reduced feed intake during heat stress impairs growth, reproduction, and immune welfare in affected flocks.
• Increased water intake during heat stress requires adequate trough provision to prevent dehydration welfare.
• Ventilation system management is the primary welfare intervention — target minimum 2m/s air speed in broiler houses.
• Evaporative cooling systems using pad coolers or fogging reduce house temperature and welfare stress.
• Cool water provision and electrolyte supplementation supports welfare during heat stress periods.
• Thinning (partial depopulation) reduces heat load within buildings, improving welfare for remaining birds.
• Broiler breed selection considering heat tolerance is an emerging welfare consideration for future production.
• Nocturnal feeding strategies align feed intake with cooler night-time temperatures, improving welfare.
• Emergency preparedness plans including equipment failure protocols protect against catastrophic heat welfare events.