Lighting management in poultry houses profoundly affects broiler and layer hen welfare — light intensity, spectrum, and photoperiod all influence behavior, health, and welfare outcomes.
Lighting management in poultry houses is one of the most accessible and welfare-significant interventions available in commercial poultry production. Continuous or near-continuous dim lighting reduces activity and increases weight gain in broilers — a production benefit achieved at welfare cost by suppressing the natural behavioral activity of birds that need to move, explore, and forage. The welfare harm of light deprivation compounds with other stressors: overcrowded, understimulated broilers on wet litter in dim conditions have measurably worse welfare outcomes than those with appropriate lighting, activity encouragement, and environmental stimulation. LED technology makes welfare-positive lighting with appropriate intensity, spectrum, and photoperiod both technically achievable and cost-competitive with conventional approaches. Regulatory requirements for minimum dark periods represent the first step; evidence-based intensity and spectrum requirements would achieve further welfare improvements.