Optimizing Standardized Ileal Digestible Methionine Requirements of White Pekin Ducks in the First 21 Days Post-Hatch

The current study investigated the optimal standardized ileal digestible (SID) methionine (Met) requirement for the growth performance of white Pekin ducks from hatching to 21 days of age. A total of 288 one-day-old male white Pekin ducklings were initially weighed and randomly assigned to six dietary groups, with six replicates per group. Eight ducklings were housed in each floor cage, pre-littered with rice hulls. Basal diets (corn-soybean-based) included 0.30%, 0.35%, 0.40%, 0.45%, 0.50%, and 0.55% SID Met, representing the dietary treatment groups. Ducklings were offered unrestricted access to experimental diets and freshwater for the duration of the study. Body weight and feed intake were recorded weekly, and the average daily gain and feed conversion ratios were calculated. Overlapping linear- and quadratic-plateau regression models were employed to estimate SID Met requirements. Final body weight, average daily gain, and feed conversion ratios in white Pekin ducks exhibited significant quadratic growth with increasing dietary SID Met concentrations. In conclusion, estimated SID Met requirements for white Pekin ducks from hatching to 21 days, based on an average of linear and quadratic model responses, were determined to be 0.51% for body weight improvement, 0.51% for average daily gain, and 0.50% for feed conversion efficiency. These findings provided invaluable insight into optimized nutritional strategies for early growth performance in white Pekin ducks.