Effects of dietary energy on growth performance and carcass quality of white growing Pekin ducks from two to six weeks of age

A dose-response experiment with 6 dietary energy levels (2,600, 2,700, 2,800, 2,900, 3,000, 3,100 kcal of AME/kg) was conducted to study the effects of dietary energy on growth performance and carcass quality of White Pekin ducks from 2 to 6 wk of age. Six hundred 14-d-old White Pekin ducks were randomly divided to 6 dietary treatments, each containing 5 replicate pens with 10 males and 10 females per pen, and these birds were raised until 6 wk of age. At 42 d of age, weight gain, feed intake, and feed: gain of ducks from each pen were measured, and 2 ducks (1 male and 1 female) selected randomly from each pen were slaughtered to evaluate the yields of abdominal fat, breast meat (including pectoralis major and pectoralis minor), and leg meat (including thigh and drumstick). As dietary energy increased from 2,600 to 3,100 kcal of AME/kg, the weight gain of ducks increased significantly, and the feed intake and feed: gain decreased significantly. According to the broken-line regression analysis, the AME requirements of White Pekin ducks from 2 to 6 wk of age for optimal weight gain and feed: gain were 3,008 and 3,030 kcal/kg, respectively, when dietary protein was 18%. On the other hand, high dietary energy did not affect breast and leg meat (P > 0.05), but abdominal fat increased (P < 0.05) when dietary AME was above 2,700 kcal/kg.