Lighting conditions in poultry housing significantly affect welfare through effects on behavior, sleep, and injury rates. Evidence-based lighting standards improve broiler and hen welfare.
Poultry lighting welfare represents a domain where industry practice has historically prioritized production metrics over evidence-based welfare. Continuous or near-continuous lighting — maintained to maximize feed intake and growth — denies birds the sleep and diurnal behavior patterns that are fundamental to their welfare. Research consistently shows that appropriate dark periods of at least 6-8 hours improve bird welfare through sleep restoration, reduced fearfulness, and better behavioral expression during light periods. The dim-light compromise used by some producers reduces but does not eliminate this welfare cost. Welfare-conscious lighting management — providing appropriate light intensity, adequate dark periods, and gradual transitions — achieves good welfare outcomes without the production penalties that producers initially feared.