Lighting in poultry houses affects bird welfare, behaviour, and health. Evidence-based lighting standards improve welfare for billions of birds.
Lighting welfare in poultry production is a scientifically clear area where relatively minor changes produce measurable welfare improvements. Continuous dim lighting in conventional broiler houses was designed to keep birds calm and reduce energy expenditure - but the effect is also to prevent natural activity, compress circadian rhythms, and create conditions associated with poor leg health and cardiovascular disease. The welfare case for minimum light levels, a regular dark period, and blue-shifted spectrum lighting is well evidenced. These improvements are achievable within existing housing infrastructure with LED retrofitting. Welfare certification schemes that include lighting standards create the market incentive for adoption.