How light intensity, duration, and spectrum affect the behaviour, health, and welfare of chickens and other poultry.
Poultry kept under continuous or near-continuous artificial lighting experience disrupted circadian rhythms, sleep deprivation, and heightened stress. Evidence shows birds need adequate dark periods for rest and recuperation. Overcrowded housing with poor lighting quality creates an environment where fearfulness and injurious pecking thrive. Providing appropriate light-dark cycles, intensity, and spectrum addresses fundamental biological needs of poultry.