Modulation of Dietry Vitamin E on Economic Characterization of Immunosupressed Laying Hens

【Objective】The modulation of dietary vitamin E levels on immunosuppressed laying hens induced by cyclophosphamide(CTX) was studied.【Method】Two hundred and seventy Nick Red laying hens were randomly divided into 5 groups and each group had 3 replications with 18 birds.Laying hens from group Ⅲ,Ⅳ,and Ⅴ(birds treated with vitamin E) were fed diets supplemented with 50,100 and 200 mg·kg-1 vitamin E,respectively,whereas group Ⅰ and Ⅱ received only the corn-soybean meal basal diets with 44.59 mg·kg-1 of vitamin E.Laying hens in group Ⅱ-Ⅳ(birds challenged with CTX) were injected in the thigh muscle with CTX at 80 body weight for 3 days,and that in groupⅠ(control group) were injected with the same amount of sterile saline.【Result】Supplemental vitamin E significantly increased egg production,feed efficiency and nutrient digestibility(P0.05).The relative weights of the spleen and thymus to the body weight,serum HI antibody titers to H5-AI,H9-AI and ND,plasma GSH-Px and SOD activities were greater in immunosuppressed birds fed supplemented vitamin E(P0.05),and the MDA concentration was least at 50 mg·kg-1 supplemental vitamin E,and further additions had negative effect(P0.05).Birds treated with CTX fed diets with supplemental 100 and 200 mg vitamin E/kg had greater plasma PGE2,IL-1,IL-6,and TNF-α levels(P0.05).【Conclusion】The results showed that dietary vitamin E supplementation significantly attenuated immunosuppressive effect of CTX challenge in laying hens.