Zinc Methionine Improves the Growth Performance of Meat Ducks by Enhancing the Antioxidant Capacity and Intestinal Barrier Function

Abstract

This study was conducted to investigate the effects of zinc methionine (Zn-Met) on the growth performance, antioxidant capacity and intestinal barrier function of meat ducks. Three hundred and sixty 1-day-old male Cherry Valley ducks were randomly divided into 6 groups with 6 replicates (10 birds each), and fed diets with 0, 30, 60, 90, 120 or 150 mg/kg Zn for 35 d. The results indicated that dietary supplementation with Zn-Met substantially increased the average daily gain (ADG), and reduced the feed to gain ratio (F/G) during 1–35 d (P < 0.05). Dietary Zn-Met markedly increased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH), and reduced the malondialdehyde (MDA) content in the jejunum (P < 0.05). The mRNA expression levels of critical antioxidant enzymes such as SOD, CAT, and nuclear factor erythroid 2-related factor 2 (Nrf2) were increased by Zn in the jejunum (P < 0.05). Supplementation with 60, 90, 120, and 150 mg/kg of Zn significantly reduced the diamine oxidase (DAO) activity in the serum (P < 0.05). Different levels of Zn can increase the mRNA expression of occluding (OCLN) and zonula occludens-1 (ZO-1) in the jejunum (P < 0.05). Diets supplemented with zinc significantly increased the content of mucin2 (MUC2), secretory immunoglobulin A (sIgA), immunoglobulin A (IgA) and immunoglobulin G (IgG) in the jejunum of meat ducks (P < 0.05). The 16S rRNA sequence analysis indicated that 150 mg/kg of Zn had a higher relative abundance of Verrucomicrobia and Akkermansia in cecal digesta (P < 0.05). In conclusion, Zn-Met improved the growth performance of meat ducks by enhancing intestinal antioxidant capacity and intestinal barrier function. This study provides data support for the application of Zn-Met in meat duck breeding.