Lighting conditions in broiler production significantly affect welfare through effects on sleep, behavior, and health, with natural light access and adequate darkness periods being welfare requirements.
Lighting is a frequently overlooked welfare factor in broiler production. Chickens evolved with natural circadian rhythms regulated by light-dark cycles, and sleep is physiologically essential for immune function, cognitive processing, and physical recovery. Near-continuous artificial lighting in commercial broiler houses creates chronic sleep deprivation across entire flocks — a welfare harm at massive scale that receives little public attention. The minimum 6-hour darkness requirement is a welfare baseline, not an aspiration. Natural light access provides the circadian cues that enable proper behavioral expression and sleep architecture.