Effects of post-hatch brooding temperature on performance of starter and growing Pekin ducks

An experiment was conducted to investigate the effects of post-hatch brooding temperature on the growth performance of starter Pekin ducks from hatch to 14 D of age and the subsequent growth performance and carcass trait of growing ducks from 15 to 42 D of age. A total of 360 one-day-old male White Pekin ducks were allocated randomly to 6 environment-controlled chambers with ambient temperature set at 26, 28, 30, 32, 34, and 36 degrees C from hatch to 7 D of age, respectively, and then decreased gradually to 26 degrees C at 14 D of age. At 14 D of age, all ducks from all chambers were transferred to a duck barn with ambient temperature maintaining from 26 to 22 degrees C and these birds continued to be raised from 14 to 42 D of age. At 14 D of age, body weight, weight gain, and feed intake decreased linearly or quadratically as initial brooding temperature increased (P < 0.05) and these performance traits were reduced when initial brooding temperature increased to 36 degrees C (P < 0.05). There was no difference in growth performance between ducks fed at brooding temperature regimen starting at 26, 28, 30, and 32 degrees C (P > 0.05). According to broken-line regression, the upper critical temperatures of the initial brooding temperature during the starter period for body weight, weight gain, and feed intake were 31.3, 31.3, and 31.1 degrees C, respectively. On the other hand, the growing ducks brooded initially at 26 or 36 degrees C had lower body weight, weight gain, and feed intake as compared to other birds brooded starting from 28 to 34 degrees C (P < 0.05), but the initial brooding temperature had no effects on carcass traits (P > 0.05). It was concluded that the upper critical temperature of the initial brooding temperature for starter Pekin ducks was 31.3 degrees C and too low initial brooding temperature could lead to growth depression during the subsequent growing period.