Light management in commercial poultry production has significant welfare implications. Understanding what different lighting systems mean for chickens helps evaluate production welfare claims.
Lighting management profoundly affects poultry welfare through its effects on circadian rhythm, sleep, activity, and eye health. The drive to maximize feed intake and growth in broiler production led to near-continuous lighting regimes that deprive birds of normal sleep patterns. Research demonstrates that continuous lighting causes ocular abnormalities and behavioral sleep deprivation in broilers. Welfare-positive lighting provides adequate dark periods for sleep, appropriate light intensity for natural behavioral expression, and natural daylight access where feasible. These welfare-positive approaches also tend to improve leg health by enabling more normal daily activity patterns. The EU's minimum 6-hour dark period represents a welfare baseline that is inadequate from a scientific standpoint but represents progress.