Artificial lighting regimes in broiler sheds are manipulated to maximise growth but often compromise sleep, circadian rhythms and welfare. Evidence supports minimum dark periods for chicken welfare.
The use of near-continuous artificial lighting in broiler production prioritises marginal growth rate gains over fundamental welfare requirements. Sleep is a biological necessity, not a luxury - chickens deprived of adequate darkness cannot consolidate memory, maintain circadian rhythms or rest adequately. The welfare cost of near-continuous lighting is compounded by its contribution to leg health problems: tired birds spend more time lying and exercise less, contributing to the muscle weakness and bone problems that cause chronic pain. The EU minimum of 6 hours darkness per 24 hours represents a baseline, not an ideal. Better welfare systems provide 8 hours of darkness with appropriate dawn/dusk simulation.