The lighting environment in broiler chicken houses profoundly affects sleep, activity, health, and overall welfare. Evidence-based lighting programmes are a key component of higher-welfare production.
Broiler chickens evolved with natural day-night cycles, and their physiology depends on regular dark periods for sleep, immune function, and leg health. Continuous or near-continuous lighting to maximise feed intake is associated with increased leg disorders, eye problems, and higher mortality. Higher-welfare standards require meaningful dark periods and adequate light intensity to support natural behaviour, reflecting the animals needs as sentient beings rather than production units.