This study was conducted to investigate effects of modified palygorskite (MPal) supplementation on the laying performance, egg quality and mineral element content, immunity, oxidative status, and intestinal integrity and barrier function of laying hens. A total of 360 52-week-old Hyline Brown hens were randomly assigned into four dietary treatments for a 7-week feeding trial. The birds were fed a basal diet supplemented with 0 (control group), 0.25, 0.5, and 1 g/kg MPal, respectively. The supplementation of MPal did not alter laying performance and egg quality among groups. Compared with the control group, MPal inclusion decreased lead (Pb) content in yolks at 49 days, and either 0.5- or 1-g/kg MPal supplementation decreased Pb accumulation in yolks at 25 days and manganese (Mn) accumulation in yolks at 25 and 49 days. The contents of jejunal secretory immunoglobulin A (SIgA), ileal SIgA, and immunoglobulin G were decreased by the dietary 0.5-g/kg MPal supplementation. The supplementation of MPal also decreased malondialdehyde content in jejunum and ileum, and decreased serum diamine oxidase activity of the laying hens at 25 and 49 days. The inclusion of 0.5 and 1 g/kg MPal enhanced villus height in jejunum and ileum, and also increased the ratio of villus height to crypt depth in ileum. In conclusion, MPal supplementation decreased Pb and Mn contents in yolks, and exhibited beneficial effects on the intestinal immunity, oxidative status, and intestinal integrity and barrier function of laying hens and its optimal dosage was 0.5 g/kg.
Keywords: Antioxidant status; Immunity; Intestinal barrier function; Laying hens; Mineral element; Modified palygorskite.