The apparent metabolizable energy requirement of White Pekin ducklings from hatch to 3 weeks of age

A dose–response experiment with 5 dietary energy levels (10.26, 10.88, 11.50, 12.14, and 12.75 MJ AME/kg) was conducted to estimate the apparent metabolizable energy requirement of White Pekin ducklings from hatch to 3 weeks of age. A total of 280 one-day-old male White Pekin ducklings were assigned to 5 experimental treatments, each containing 8 replicate pens with 7 birds per pen. These ducklings were reared in raised wire-floor pens from hatch to 21 days of age. At 21 days of age, the weight gain, feed intake, energy intake, protein intake, feed conversion efficiency, and the yields of abdominal fat, breast meat, and leg meat of ducklings from each treatment were measured. As dietary energy level increased from 10.26 to 12.75 MJ AME/kg, the weight gain of ducklings increased (P<0.01) and the feed intake, feed conversion efficiency and protein intake decreased (P<0.01), but the energy intake did not change (P>0.05). According to the broken-line regression analysis, the AME requirement of White Pekin ducklings from hatch to 3 weeks of age for optimal feed conversion efficiency was 12.63 MJ/kg when dietary protein was 205 g/kg. A high dietary energy content did not affect (P>0.05) the percentage of breast and leg meat in the carcass but the percentage of abdominal fat increased (P<0.01) as dietary energy level increased.