Effects of Dietary Artemisia argyi Powder on Growth Performance, Slaughter Traits, Organ Indices, Intestinal Morphology, and Serum Biochemistry and Antioxidant Status in Female Linwu Ducks During the Late Growing Phase

This study evaluates the effects of dietary Artemisia argyi powder (AAP) on female Linwu ducks during the late growing phase. A total of 384 ducks, initially 87 days old, were randomly allocated to four treatments with four replicates of 24 ducks each. Ducks received a basal diet supplemented with 0%, 2%, 4%, or 6% AAP for 26 days. Growth performance, slaughter traits, and organ indices showed no significant overall treatment effects (p > 0.05). Jejunal crypt depth decreased in all AAP groups compared with the control, whereas ileal crypt depth decreased in the 4% and 6% groups compared with the control (p < 0.05). Supplementation with 6% AAP increased serum albumin and urea nitrogen concentrations (p < 0.05). Serum malondialdehyde concentrations decreased in all AAP groups, and total superoxide dismutase activity increased in the 4% and 6% groups (p < 0.05). A quadratic model estimated minimum jejunal crypt depth at approximately 4% AAP. Dietary AAP was therefore associated with changes in intestinal morphology and serum antioxidant markers without detectable growth or slaughter benefits. This model-derived inclusion level is an exploratory estimate and requires independent validation before practical use.