The effect of light regime on growth and pattern of body fat accretion of broiler chickens.
A seven week serial slaughter experiment was conducted with male and female broiler chickens to determine the effect of photoperiod on body growth rate and pattern and rate of fat deposition. The two light regimes compared were constant light and a 16 hour light:8 hour dark photoperiod. Males grown under the 16L:8D photoperiod consumed less feed and grew less rapidly than males under constant light. The slower rate of growth was apparently due entirely to less feed consumption, since feed efficiency of males was unaffected by light treatment. Females reared under 16L:8D also grew less rapidly than under constant light. However, the difference was much more pronounced than in males, and was not due to reduced feed consumption, rather to less efficient feed utilization. Females grown under 16L.8D exhibited a slower rate of increase in percent daily fat gain than did females grown under constant light. At seven weeks of age, total body fat content of females averaged 12% less when grown under 16L:8D. Rat and pattern of fat gain in males was unaffected by light treatment. The incidence of leg abnormalities was substantially lower for both sexes reared under 16L:8D.
D000273:Adipose Tissue / Q000502:physiology*; D000818:Animals; D001835:Body Weight; D002645:Chickens / Q000254:growth & development*; D002940:Circadian Rhythm; D004435:Eating; D005260:Female; D006128:Growth; D008027:Light; D008297:Male; D012737:Sex Factors