ENHANCEMENT OF HUMORAL AND CELLULAR-IMMUNITY BY VITAMIN-E AFTER EMBRYONIC EXPOSURE

In the present study, the amnion of turkey and chicken embryos were in jected 3 d prior to hatch with different levels of vitamin E (VE). In Experiments 1 and 2, turkey embryos received 10, 20, and 30 IU of VE. In Experiment 3, broiler embryos received 10 IU VE. In all three exper iments, sham-injected control embryos (0 IU VE) received 300 mu L of s aline. In Experiments 1 and 2 (turkey embryos), 20 and 30 IU of VE red uced (P less than or equal to 0.05) percentage hatchability below that of controls. At hatch, poults exhibited a dose related increase (P < 0.05) in plasma VE levels. Mean BW gain up to 35 d and relative bursa of Fabricius and spleen weights were not different among treatment gro ups. When challenged at 7 d posthatch, total (P < 0.05) and IgM (P < 0 .08) anti-SRBC antibodies were higher in 10 IU VE poults than in contr ols. Immunoglobulin G levels did not differ among the treatment groups . Poults in the 10 IU VE group had higher (P < 0.002) numbers of Sepha dex-elicited inflammatory exudate cells, as well as a greater percenta ge of phagocytic macrophages (P < 0.0001). Additionally, the numbers o f SRBC per phagocytic macrophage were greater (P < 0.001), than in con trol poults at 4 wk of age. In Experiment 3, chick embryos exposed to 10 IU VE, exhibited no differences in hatchability, BW gain, or bursal and splenic weights from the sham-exposed group. However, total and I gM antibody responses against SRBC were greater (P < 0.01) in the 10 I U VE group at 7 d postinjection. A secondary SRBC challenge given at 1 4 d after primary injection resulted in higher total (P < 0.07) and Ig G (P < 0.04) antibody responses in the 10 IU VE chicks than in the con trols. Similarly, broiler chicks (10 IU VE) had more Sephadex-elicited abdominal exudate cells (P < 0.07), and greater macrophage phagocytic potential (P < 0.0001). In ovo VE exposure (10 IU) also increased nit rite production (P < 0.04) by chick macrophages. The results from this study demonstrated an enhanced antibody and macrophage response and s uggest that in ovo exposure with VE may improve posthatch poult and br oiler quality.