Abstract
Environmental enrichment, such as lighting, has affected the behaviors, welfare, and production of commercial broiler chickens. However, most studies have focused on constant light intensities to determine their effect on welfare and performance. Research indicates that the significant contrast of light intensities in broiler houses promotes pronounced daily patterns of behavior and activity, impacting broiler chicken health. Birds exhibited preference behaviors in bright-intensity light during active behaviors, such as eating and drinking, but in darker areas when resting. Light intensity preferences may be associated with the voluntary instinctive movement of birds by providing choices for birds. Increasing broiler chickens' movement may boost welfare, especially leg health, which is a leading cause of culling and late mortality in commercial production. In this review, we discuss the progress and results of practical environmental enrichments, enrichment lighting, and huts in commercial broiler houses. We briefly address interpretations of improved welfare and performance and suggest directions for future research that may interest poultry scientists.