Lighting programs in poultry production significantly affect bird welfare through effects on rest, activity patterns, and behavioral expression, with optimal programs supporting natural circadian rhythms.
Poultry lighting programs affect welfare through both acute effects on sleep and activity and longer-term physiological consequences. Continuous or near-continuous lighting denies birds sleep and rest periods that are fundamental welfare needs. The transition to lighting programs with appropriate dark periods represents one of the easiest and most impactful welfare improvements available to poultry producers, requiring no infrastructure change beyond timer modification. Welfare certification requirements for minimum dark periods are now standard in most higher-welfare schemes.