Effects of zinc oxide-montmorillonite hybrid on growth performance, intestinal structure, and function of broiler chicken

A total of 450 one-day-old Arbor Acres male chickens were used to investigate the effects of zinc oxide-montmorillonite hybrid (ZnO-MMT) on growth performance, intestinal structure, and function. The birds were allotted to 5 dietary treatments for 21 d, each of which was replicated 6 times with 15 chicks per replicate. The dietary treatments were 1) corn-soybean meal diet (basal, containing 42.35 mg of Zn/kg); 2) basal diet + 600 mg of MMT/kg (equivalent to the MMT in the ZnO-MMT treatment); 3) basal diet + 60 mg of Zn/kg as ZnO; 4) basal diet + 60 mg of Zn/kg as ZnO-MMT; and 5) basal diet + 60 mg of Zn/kg as ZnSO4 center dot 7H(2)O. The results showed that chicks fed ZnO-MMT had higher (P < 0.05) ADG and feed intake than those fed the basal diet, MMT, or ZnO. Compared with the control, MMT, ZnO, or ZnSO4, supplementation with ZnO-MMT decreased (P < 0.05) viable counts of Clostridium in small intestinal and cecal contents, increased (P < 0.05) colonic transepithelial electrical resistance (TER) values, and reduced (P < 0.05) colonic probe mannitol permeability as well as ileal or colonic inulin permeability. Compared with the control, supplemental ZnO-MMT increased (P < 0.05) villus height, the ratio of villus height to crypt depth at the small intestinal mucosa, the trypsin activity in the pancreas, and the digestive enzyme activities in small intestinal contents. Compared with the control, supplementation with ZnO increased (P < 0.05) the villus height and the villus height to crypt depth ratio at the duodenum. Supplementation with ZnSO4 increased the trypsin activity in pancreas and small intestinal contents. However, supplemental MMT, ZnO, or ZnSO4 did not affect (P > 0.05) growth performance, ileal and colonic barrier function, and intestinal microflora. The results indicated that supplementing 60 mg of Zn/kg as ZnO-MMT in broiler chickens improved growth performance, intestinal microflora, intestinal morphology, and barrier function as well as the digestive enzyme activities.