The effect of light duration on turkey poult performance and adrenal function.
Day-old tom poults were exposed to one of the following light treatments: 1) continuous incandescent light (24LL), 2) 23L:1D incandescent light, 3) 12L:12D incandescent light, or 4) natural day lengths only. Mortality was recorded daily. At Weeks 1, 2, 4, 6, and 8, after poult placement, body weights and feed consumption were measured. At each of these times, 10 poults were sacrificed from each treatment group for evaluation of plasma corticosterone. Day lengths utilized in this study had no consistent effect on poult-performance parameters except from 0 to 2 weeks of age. During this time, poults in the 24LL and 23L:1D treatments consumed less feed but were similar in body weight to poults in the other treatments. Adrenal function was also not consistently affected by day length. However, in all treatment groups plasma corticosterone was lowest during the first 2 weeks posthatching, when compared to hormone levels at 4, 6, and 8 weeks. The lower corticosterone that occurred during the first 2 weeks posthatching may be involved in early poult mortality.
D000302:Adrenal Cortex / Q000502:physiology*; D000311:Adrenal Glands / Q000033:anatomy & histology; D000818:Animals; D001835:Body Weight; D003345:Corticosterone / Q000097:blood; D004435:Eating; D008029:Lighting; D008297:Male; D009026:Mortality; D009929:Organ Size; D014422:Turkeys / Q000502:physiology*
D003345:Corticosterone