Lighting regimes significantly affect broiler welfare - photoperiod manipulation affects growth, sleep, activity and metabolic health in ways that welfare science is clarifying.
Broiler lighting welfare science demonstrates how production priorities have historically overridden welfare considerations. Continuous lighting maximises growth rate by maximising feeding time but compromises sleep, rest and normal diurnal behaviour. The minimum dark period requirement represents a welfare floor below which sleep deprivation welfare harms become substantial. Research into optimal photoperiods balancing welfare and production shows meaningful dark periods of at least 8 hours improve welfare outcomes without proportionate production penalties. Natural light provision further improves welfare through enriched visual environment and more natural behaviour expression.