Effects Of High Level Of Tin On Intestinal Immune Function And Microbial Flora In Broiler Chicken

Tin,as one of the essential trace elements of organism,has many physiological functions.The trial was conducted to study the effect of different tin levels on intestine of broilers.A total of two hundred forty one-day-old healthy yellow-feather broilers were randomly assigned at four groups.The control group was fed by the basal diet,and the other three groups were kept on the basal diet along with supplementation of the tin content of 400,800 and 1200 mg/kg stannous chloride for 42 days.In this study,the clinical observation,histopathology,biochemistry,enzyme-linked immunosorbent assay(ELISA)and polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)techniques were used to investigate the effects of dietary high tin on intestinal pathological change,antiocidant function,mucosal immunity?and microbiota in broilers.Results?were?shown?belowR1.Comparison of high tin group and control group,the high tin group II?III length of the intestinal tract was significantly lower than that of the control group(P<0.05 or P<0.01);The intestinal mucosa epithelial cells appeared denaturation,necrosis and falls off in the intestinal tract of the high tin group II?III in broilers;and the histomorphological parameters such as villus height,crypt depth and the ratio of the villus height and crypt depth were significantly decreased(P<0.05 or P<0.01).2.Compared with the control group,The MDA content of intestinal mucosa of the high tin group II?III increased significantly(P<0.05 or P<0.01);the content of GSH was significantly decreased(P<0.05 or P<0.01);the activity of CAT?T-SOD enzymes were significantly decreased(P<0.05 or P<0.01).3.The results of ELISA detection showed that the IgA,IgG,and IgM levels were significantly lower(P < 0.05 or P < 0.01)in the high tin group I,II and III than those in the control group.4.Using polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)techniques to investigate the effects of high tin in broiler diets on the intestinal microflora ecology.The results shown that the diversity?(the species richness,similarity and?Shannon?indec)and composition of the gut flora in the high tin group II and III were significantly altered when compared with the control group,which disturbed the gut ecosystem and further triggered diarrhea of broiler chickens.In conclusion,the results in the present study suggestted that dietary tin up to 400 mg/kg and above could impair the function of intestinal?mucosal immunity,restrained the growth and development of broilers.Dietary tin up to 800 mg/kg and above could cause small intestinal villus degeneration,fall off,crypt shrinking,which changed the morphology of the intestinal tract in broilers;decreasd the diversity and altered composition of the intestinal microbiota.In addition,dietary tin up to 800 mg/kg and above could cause ocidative stress in the intestinal tract,thereby damaging the antiocidant function of the intestines and harmful to the health of the broilers.