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°C from hatch to 7 D of age, respectively, and then decreased gradually to 26°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°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°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°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°C, respectively. On the other hand, the growing ducks brooded initially at 26 or 36°C had lower body weight, weight gain, and feed intake as compared to other birds brooded starting from 28 to 34°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°C and too low initial brooding temperature could lead to growth depression during the subsequent growing period.