The Effect of Intermittent Lighting on Growth, Feed:Gain Ratio, and Abdominal Fat Content of Broiler Chickens of Various Genotypes and Sex

Abstract

Intermittent lighting (IL) regimens were tested for rearing broiler chickens from 2 to 7 weeks of age. In Experiments 1 and 2, the effects of 6 cycles of light (L) and darkness (D) of 1L:3D vs. 12 cycles of .25L:1.75 D were compared on the performance of 2400 broiler chickens. Eight genotypes of 5170 mixed-sex broilers were used to compare effects of 6 cycles of 1L:3D vs. 1 cycle per day of 23.5L:.5D on broiler performance (Experiment 3). The sexes responded differently to two IL regimens in Experiment 1. Males had higher body weight, feed intake, and abdominal fat content with 1L:3D; in females, there was no difference in body weight or feed intake, but abdominal fat content was lower with 1L:3D regimen. In Experiment 2, no significant effect of lighting regimen on broiler performance was observed. In Experiment 3, most genotypes had lower feed intake and abdominal fat content for 1L:3D than for 23.5L:.5D, but response of weight gain was variable; one genotype had higher feed intake and another genotype had higher fat content with 1L:3D. It was concluded that sex and genotype should be considered in planning the use of IL techniques for broiler chickens.