Effect of photoperiod and light intensity on the performance of intact male turkeys

Abstract

AbstractInjurious pecking can be a major cause of mortality in growing turkeys, particularly if given a long photoperiod. Consequently, birds are usually reared under low light intensity (<1 lux) and/or have their beaks trimmed. The influence of an 8, 12, 16 or 23 h photoperiod at an intensity of 1 or 10 lux on the performance of intact (not beak trimmed or de-snooded) BUT8 male turkeys was assessed in a 4 X2 empirical study.Excessive injurious pecking in groups exposed to 10 lux light intensity on >12 h photoperiods necessitated an unscheduled reduction to 1 lux light intensity. Overall, light intensity did not significantly affect food intake, food conversion efficiency, growth or carcass composition. Groups exposed to 10 lux light intensity for all or part of the trial had higher losses and a greater incidence of pecking than birds maintained on al lux light intensity.Growth was inconsistently affected by photoperiod, with birds on 12 h having the highest body weight at 108 days but no significant differences at 136 days. Patterns of food intake were variable but cumulatively to 136 days food intake was not significantly affected by daylength. Overall, but particularly after 108 days, birds on longer photoperiods converted food more efficiently. Mortality and the incidence of injurious pecking was positively correlated with photoperiod and breast meat yield and testicular weight were greater in birds on longer daylengths. There were no significant interactions between photoperiod and illuminance.