Broiler Chicken Lighting and Circadian Welfare

How lighting programs in broiler production affect chicken welfare through circadian rhythm disruption and its health consequences.

Key Facts

Conventional broiler production uses continuous or near-continuous lighting to maximize feed intake and growth rate.
Chickens have a strong circadian clock that regulates sleep, metabolism, immune function, and behavior.
Disrupting circadian rhythms through continuous lighting causes immune suppression and increases disease susceptibility.
Minimum dark periods of 6-8 hours significantly improve broiler health and welfare outcomes.
EU regulations require minimum 6-hour dark periods for broilers, with 1-hour uninterrupted dark.
Dim intermittent lighting programs achieve some production goals while providing more circadian rest.

Welfare Considerations

Lighting management in broiler production represents a conflict between short-term productivity maximization and fundamental welfare needs. Chickens, like all vertebrates, require adequate dark periods for circadian regulation that affects virtually every physiological system. The welfare costs of continuous lighting include poor sleep quality, immune compromise, and increased susceptibility to respiratory and enteric diseases. Regulatory minimum dark periods represent a floor that welfare-focused producers should exceed. Full-spectrum lighting programs that mirror natural day length provide optimal welfare outcomes while maintaining acceptable production performance. Consumer awareness of lighting practices is low, making it a hidden welfare issue where regulatory action is more effective than market pressure.

What You Can Do

Support regulatory minimum dark period requirements for broiler facilities in your jurisdiction.
Choose chicken products from farms certified under welfare programs specifying lighting standards.
Advocate for lighting standards that provide sufficient dark periods for circadian regulation in poultry.
Support research into optimal lighting programs that balance production efficiency with welfare needs.