Effects of daidzein on antioxidative activities and immune functions in dairy cows

Forty healthy Chinese Holstein dairy cows with the near calving number,output of milk and lacation were divided randomly into four groups(n=10).Daidzein was added into the diets of dairy cows at the dosage of 45,60,75 mg/kg,respectively,but control group fed on the basal diets during 60 days experiment.Blood samples were collected from jugular vein at intervals of 0,10,30,60 days after administration to examine the activities of SOD,CAT,GSH-Px and the contents of MDA in serum,lymphocyte transformation rate and T cell count in blood.The results showed that activities of serum SOD,CAT,GSH-Px enhanced remarkably in comparison with before experiment(P0.05 or P0.01);the MDA contents were significantly lower than those of the before feed daidzein(P0.01);Lymphocyte transformation rate and T cell count in 60-70 mg/kg supplement group were higher(P0.05) than those of control.