Providing broiler chickens with adequate dark periods for sleep and rest is a fundamental welfare requirement frequently violated in intensive systems where near-continuous lighting is used to maximize feed intake.
Broiler chickens deprived of adequate darkness for rest experience chronic sleep deprivation that compounds the welfare problems arising from fast growth. Natural circadian rhythms regulate immune function, bone metabolism, and pain sensitivity — disrupting these through continuous lighting worsens the health problems already caused by extreme growth rates.