This experiment was conducted to study the effects of dietary zinc level on growth performance,antioxidant function,and immune organ development of caged egg-type ducklings.Using a single factor completely randomized design,a total of 180 one-day-old Jinding egg-type ducklings were randomly divided into 5 groups with 6 replicates per group and 6 ducks in each replicate.Ducks in control group(group Ⅰ) were fed a basal diet,and the others in experimental groups(groups Ⅱ-Ⅴ) were fed the basal diet supplemented...