Growth performance, zinc tissue content, and intestinal health in meat ducks fed different specific surface area of micronized zinc oxide.

This study investigated the effect of different specific surface area micronized zinc oxide (ZnO) on growth performance, zinc (Zn) tissue content, jejunal morphology, jejunal antioxidative status, and intestinal mucosa barrier-related gene expression in meat ducks. A total of 480 one-day-old Cherry Valley ducks were randomly divided into 4 dietary treatments, which each had 12 replicates; therefore, each replicate consisted of 10 ducks. Experimental diets included the basal diet supplemented with ZnSO4 (control group) and 3 different treatments of specific surface area micronized ZnO, in which the specific surface area was either 11.30 m2/g (S-mZnO), 20.90 m2/g (M-mZnO), or 34.02 m2/g (L-mZnO). The amount of Zn extra supplementation in the 4 diets was 120 mg/kg of diet. The experiment lasted for 35 D. The results showed that supplementation of M-mZnO significantly increased (P < 0.05) the BW (35 D), the BW gain (14 to 35 and 1 to 35 D), the jejunal crypt depth, and mRNA expression of zonula occludens-3, mucin 2, and secretory immunoglobulin A of ducks, while the feed-to-gain ratio (14 to 35 and 1 to 35 D) significantly decreased (P < 0.05) when compared to the control and the other 2 supplementation groups. Furthermore, compared with control group, the hepatic Zn content and the jejunal superoxide dismutase activity in the 3 micronized ZnO groups were significantly increased (P < 0.05), and the Zn content in the pancreas tended to increase (P = 0.051). In conclusion, this study demonstrates that M-mZnO as a dietary supplement can improve the growth performance of meat ducks by increasing the Zn tissue content and improving intestinal morphology, antioxidative status, and physical, chemical, and immunological barrier function.