Lighting programs for poultry affect health, behavior, and welfare through their influence on circadian rhythms, activity levels, and production cycles.
Lighting management in poultry production significantly affects welfare through its influence on rest, circadian rhythm, activity, and behavior. Near-continuous lighting used to maximize feed intake disrupts sleep patterns and normal behavioral rhythms, causing chronic fatigue and stress. Minimum dark periods allow birds to rest and express diurnal behavior patterns aligned with their biological programming. Wavelength and intensity of light affects fearfulness and aggression — dimmable systems with appropriate spectrum can create calmer, more behaviorally normal flocks. The welfare case for improved lighting programs is supported by both welfare science and production evidence that well-rested birds with appropriate light cycles have better immune function and health outcomes.