The Influence of Intermittent Light on Growth of Broilers

Ten treatments involving continuous, constant intermittent, and variable intermittent light were conducted over five trials to determine the effect of these light regimes on weight, gain in body weight, and feed efficiency in broilers. The chicks were grown in battery brooders and were on experiment from one to seven weeks of age. In four trials in which both treatments were used, chicks grown with 30 min of light and 150 min of darkness per 3-hr cycle had an average body weight of 67 g more at seven weeks of age than those grown under continuous light. The differences were statistically significant (P<.05 or P<.01) in three of these trials. In four trials in which comparisons were possible, chicks grown under 30 min light and 150 min of darkness per 3-hr cycle averaged slightly, but not significantly, more (19 g) at seven weeks of age than those under other constant intermittent light schedules. Chicks grown under 30 min light and 150 min of darkness per 3-hr cycle averaged slightly more (23 g) than thos under variable intermittent light treatments. Differences were significant (P<.05) in only one of three trials in which comparisons were possible. Gain per unit of feed consumed from one to seven weeks of age was not significantly different among treatments within each trial.