| Abstract: | A total of 468 male turkeys which had been fed ad libitum and received light for 23 h each day for the first 6 weeks oflife were used to study the effects of subsequent lighting pattern on performance. Three lighting treatments were used: a constant 23 h/d (L1), a constant 14 h/d (L2) and a step‐down pattern in which the light period was reduced from 22 h/d, by 1 h each week, to 14 h/d at 14 weeks, after which it was kept constant until 18 weeks (L3). Within each lighting treatment there were two feeding treatments: birds were either offered food ad libitum or received a restricted amount of food that was the same for all lighting treatments. At 18 weeks of age there was no difference between body weights of birds receiving treatments L2 and L3, but birds receiving treatment Li were significantly (P< 0.05) heavier. This difference was independent of feeding treatment. Despite the difference in body weight voluntary food intake was slightly greater in birds receiving treatment L2 than in those receiving Li. As a result, a significantly (P < 0.01) more efficient food conversion was associated with L1 than with L2 and L3. |
