Lighting programs in poultry production profoundly affect chicken welfare through their influence on behavior, sleep, physiology, and the expression of natural behavioral drives.
Lighting management is a relatively low-cost welfare intervention with significant impacts on chicken wellbeing that is frequently misimplemented in commercial production. Continuous or near-continuous lighting maximizes feeding time and growth rate but causes sleep disruption that compounds other welfare harms in intensive broiler production. The evidence that adequate dark periods improve leg health — already a severe welfare concern in rapidly growing commercial breeds — creates a direct link between lighting welfare and one of broiler production's most serious welfare problems. Appropriate lighting programs that provide dark periods, appropriate spectrum, and sufficient intensity for natural behavior are achievable without significant cost penalties and represent one of the more straightforward welfare improvements available to the industry.