Lysine, Methionine and Tryptophan Requirements of Beijing Ducklings of 0–2 Weeks of Age

A feed trial was conducted with a total of 1 134 Beijing ducklings to study the optimum level of dietary lysine (Lys) (0.95, 1.10, 1.25%), methionine (Met) (0.26, 0.46, 0.66%) and tryptophan (Trp) (0.20, 0.30, 0.40%) for those ducklings during a phase of 0–2 weeks. Ducklings were randomly allotted to 27 groups according to a 3 × 3 × 3 factorial arrangement and fed a basal corn-soybean-peanut meal diet containing 20.26% CP, 12.45 MJ kg−1 ME. The results from this study indicate that Lys affected body weight (P<0.01), feed intake (0–14 d) (P<0.01), but had no effect on feed/gain (0–14 d) (P>0.05), uric acid concentration (P>0.05). Methionine influenced body weight (P<0.01), feed/gain (P<0.05), and feed intake (P<0.01). Tryphtophan had no effect on indices measured. The requirement of the Lys and Met for Beijing ducklings of 0–2 weeks of age were 1.10 and 0.46%. The requirement of Trp for Beijing ducklings of 0–2 weeks of age was not more than 0.20%.