Poultry Lighting and Circadian Welfare

How lighting management in poultry farming affects circadian health, behavior, and welfare.

Key Facts

Conventional broiler farming often maintains 23 hours of light per day to maximize feeding and growth
Constant or near-constant lighting disrupts circadian rhythms, causing sleep deprivation in chickens
Chickens denied dark periods show elevated stress hormones and impaired immune function
EU legislation now requires minimum dark periods for broiler chickens but enforcement varies
Intermittent lighting programs can maintain production while significantly improving welfare outcomes
Natural or simulated dawn-dusk cycles substantially improve chicken welfare indicators

Welfare Considerations

Poultry lighting is a welfare issue where commercial incentives directly conflict with animal physiological needs. Chickens are diurnal animals whose biology is organized around light-dark cycles that regulate sleep, immune function, and hormonal rhythms. Constant illumination to drive feeding behavior is a form of chronic sleep deprivation at industrial scale. The welfare case for mandatory dark periods and dawn-dusk lighting programs is strong, and the production evidence shows minimal impact on growth rates when lighting is managed appropriately.

What You Can Do

Choose poultry products from farms with certified lighting programs providing adequate dark periods
Support regulations mandating minimum dark periods and natural light access for poultry
Advocate for enforcement of existing lighting standards in broiler production
Support welfare science research on optimal lighting conditions for poultry species