Effects of modified montmorillonite adsorbent on performance, egg quality, serum biochemistry, oxidation status, and immune response of laying hens in late production

This study was conducted to investigate the effects of dietary supplementation with calcium montmorillonite (Ca-MMT) on layers' oxidation status, immune response, serum biochemistry, performance, and egg quality. A total of four hundred-eighty 75-wk-old laying hens were randomly assigned to 5 treatments with 8 replicates per treatment and 12 hens in each replicate. The hens were fed the basal diet supplemented with 0, 0.3, 0.6, 0.9, or 1.2 g Ca-MMT/kg for 70 d. The Ca-MMT supplementation linearly or quadratically (P < 0.05) increased yolk index, serum total superoxide dismutase activity, and interleukin-2 and immunoglobulin G concentrations at d 35, and shell thickness, and serum and liver glutathione peroxidase activity at d 70. With increasing supplementation of Ca-MMT in the basal diet, serum activity of alkaline phosphatase decreased both linearly and quadratically (P < 0.05) at d 35, and alanine aminotransfer as activity and tumor necrosis factor-alpha concentration decreased linearly or quadratically (P < 0.05) at d 70. The evidence indicates that increasing Ca-MMT concentration improved yolk index and shell thickness, and partially enhanced hens' antioxidant capability and immune function.