Effects of light and temperature on anticipatory feeding by broilers.

The objective of this research was to determine the effects of daily cycles of light intensity and temperature on anticipatory feeding by broilers. Broilers were maintained on litter in environmental chambers with feed provided for 12 h/d. Feed consumption was recorded by computer every 30 min and summarized for 2- and 24-h periods. In Trial 1, lighting was at 16 lx for 12 h and at 94 lx for 12 h each day. Feed was provided either during the 16- or 94-lx period. Broilers consumed more feed at the onset of feeding and at the end of the feeding period than at other times in both treatments. In Trials 2 and 3, the chamber temperature was cycled such that a 12-h feeding period was provided at either 32 or 16 C. Broilers consumed more feed at the onset of feeding than at other times but did not increase consumption at the end of the feeding period. The results indicate anticipatory feeding is enabled by cyclic lighting intensity but not by cyclic temperature. In Trial 4, the light intensity and temperature were cyclic. Feed was provided during high light intensity and at maximum temperatures. Feed consumption increased when temperature was declining, indicating broilers responded to the reduced temperature. The results show that a period of darkness is not required for anticipatory feeding and that environmental temperatures and lighting typical of curtain-sided broiler houses alter feed consumption patterns.