The Effect Of Different Levels Of Protein Diets Supplement With Different Level Of Zinc On Growth Performance,Antioxidation And Intestinal Mucosa Immunity Of Earley Weaned Piglets

A 2x3 mulitiple-factor experiment was conducted to study the effect of different zinc and protein levels on growth performance,antioxidant function and intestinal mucosa immunity in early weand piglets for 21±2d.Fourty-eight weaned DLY pigs with age of 21±2d and initial were randomly assigned to six treatments according to gender and BW by 2*3.Each treatment had four replicates and each replicate has two piglets.Zn supplement amounts were 100 and3000 mg/kg,protein level were 23%,20%and 17%.The six treatments were low zinc(100 mg/kg) and high protein(23%) group;low zinc(100 mg/kg) and middle protein(20%) group;low zinc(100 mg/kg) and low protein (17%)group;high zinc(3000 mg/kg) and high protein group(23%);high zinc(3000 mg/kg) and middle protein(20%) group;high zinc(3 000 mg/kg) and low protein group(17%);The results showed that:1) Different level of protein diets supplementation with high dosage of zinc can improve growth performance and degrade diarrhoea of the weaned piglets,The piglets fed high level of protein and high dosage of zinc had a better growth performance than other groups(P＜0.05).And in the low level of zinc group and high level of zinc group,with protein level increasing the average daily growth increased,and the high level of zinc group had a better ADG than low level of zinc group(P＜0.05),and the ADFI also lower than the low level of zinc group(P＜0.05).2) Different level of protein diets supplementation with high dosage of zinc can significantly increase serum GSH and CuZn-SOD concentration(P＜0.05).in low level of zinc group and high level of zinc group,whith the protein level increasing,the concentration of GSH and CuZn-SOD increased significantly(P＜0.05).the high level of zinc group was better than low level of zinc group.3) Different level of protein diets supplementation with high dosage of zinc can significantly increase serum IgA,IgG and IgM concentration(P＜0.05).Degraded serum interleukin-1βand interleukin-6 concentration(P＜0.05).in low level of zinc group and high level of zinc group,whitb the protein level increasing,the concentration of immunoglobulin increased significantly(P＜0.05).The IL-1βand IL-6 concentration also had the same regular.The high level of zinc group's immunoglobulin concentration was higher than low level of zinc group,and IL-1βand IL-6 concentration was lower than low level of zinc group.4) Different level of protein diets supplementation with high dosage of zinc can increase villus length and degrade the depthe of crypt(P＜0.05),and also increased the ratio of Villus/Crept.5) Different level of protein diets supplementation with high dosage of zinc can increase the concentration of intestinal mucosa SIgA,IL-2,IL-4(P＜0.05).and also degrade IFN-γcontentration.Supplementation with high dosage of zinc maintain the equilibrium of Th1/Th2 system.So,it can be said that:Different level of protein diets supplementation with high dosage of zinc can improve the growth performance,anti-oxidant function and humoral immunity function.and high dosage of zinc also improve intestinal mucosa immiunity,maintain the equilibrium of Th1/Th2 system.Promoted the development of intestinal of the early weaned piglets.