Lighting conditions in broiler chicken houses profoundly affect behavior, health, and welfare, with evidence-based standards now informing better practices in the industry.
Chickens are diurnal animals requiring a dark rest period for healthy sleep, hormone regulation, and eye development. Extended light periods used to maximize feeding and growth cause chronic sleep deprivation, retinal damage, and elevated stress hormones. Welfare-progressive lighting standards that provide adequate darkness, natural spectrum light, and gradual transitions between light and dark periods produce measurable improvements in bird wellbeing as measured by behavior, health indicators, and fear responses.