Lighting management in broiler chicken houses significantly affects welfare. Light intensity, spectrum, and photoperiod influence behavior, health, and the ability of chickens to express natural activities.
Lighting in broiler production is a welfare lever that has historically been used against animals. Near-darkness suppresses movement, preventing activity that burns calories and keeping birds quiet. The welfare cost is profound: birds without adequate light cannot perform normal behaviors, develop abnormal eye structures, and cannot rest and be active in natural cycles. Modern welfare standards recognize adequate light as a fundamental requirement. The connection between lighting and leg health is particularly important - active birds with adequate light develop stronger musculoskeletal systems that reduce the crippling lameness that affects a significant proportion of fast-growing broilers.