Effect Of Feather Meal Chelated Copper And Manganese On Growth Performance And Immune Function Of Weaned Piglets

In order to relieve livestock pollution and realize swine cleaner production,content of copper and manganese was lowered through replacing inorganic form with chelated form which was proven to have a higher bioavailability,without lowering growth rate.In this paper,effect of several proportions of Hydrolyzed feather meal Chelated copper and manganese on growth performance and immune function of weaned piglets were studied.Experiment 1:five little of 70 Duroc-lanndrae-Yorkshire cross weaned piglets about 10-12kg body weight were divided into five groups(A,B,C,D and Control).cheated copper and manganese in trial diets were replaced in corporation with control group,with 80%copper and 80%manganese in group A,60%copper and 80%manganese in group B,80%copper and 60%manganese in group C,60%copper and 60%manganese in group D.after 21-day,compared to control group,group D had similar average daily gain(ADG) to control group,while ADG of group A(0.66kg per day) raised by 8.2%,group B(0.63kg per day) by 3.3%,group C(0.63kg per day) by 3.3%,respectively. In case of feed/gain(F/G),group A＜group B＜group C＜group D and control group.In case of diarrhea rate,result was similar to feed/gain and found group A best,group B next.Experiment 2:trial animal,group dividing,diet formula and experiment design were same to experiment 1.Ten piglets were randomly sampled and 5ml blood was drew from precaval vein,during 7:00-9:00a.m.at 7^th and 21^th day.blood coagulated and was centrifuged at 3000r/min for 1-2 minutes.separated serum was conserved at 4℃for late use of detecting activity of superoxide dismutase(SOD) and glutathione peroxidase(GSH-PX).Results suggested:group B achieved best SOD activity than the other groups,and either group B or group C had stable SOD and GSH-PX activity with a certain degree of rising inclination;when separately analyzed, GSH-PX activity rose as age,among which group C increased the most while group B,C,D all reached statistically significant level.Experiment 3:trial animal,group dividing,diet formula and blood drawing schedule were same to experiment 2.Content of serum immunoglobulin including IgA,IgG and IgM,was measured. Results indicated:content of IgA and IgM in group A significantly increased early at 7^th day; content of IgG in all groups didn't significantly differ;totally,content of immunoglobulin in all groups had no significant change at 7^th day and 21^th day.Experiment 4:trial animal,group dividing,diet formula and blood drawing schedule were same to experiment 2.Swine Fever(SF) antibody blocking rate was compared between all groups. Results showed:group C had a significantly higher blocking rate,while group A,B and D better than control group,but not significantly.At 7^th day,all trial groups were better than control group;at 21^th day,except group D,group A,B and C,had significantly effect.Totally,group A(80%chelated copper and 80%chelated manganese) could serve as optimal scedule,although several replacing proportions of chelated copper and manganese had no agreeable effect on growth performance and immune function of weaned piglets.