RESUMEN
The effects of selenium-enriched yeast (Sey) on DTH in immunosuppressive mice have been investigated. It was found that Sey (30, 60, 90 mg?kg-l?d-1?6 d, ig) was able to antagonize lowered DTH by cyclophospha-mide (Cy); Meanwhile, the thymus and spleen weights were increased by Sey (30, or 60 mg?kg-1?d-1) in immunosuppressive mice. Sey also potentiated the lowered ConA and LPS-indu-ced proliferation of splenocytes in DTH mice at the doses of 30, 60, or 90 mg ?kg-1 and 60 or 90 mg?kg-1 respectively. These results suggested that Sey could enhance the functions of lymphocytes.
RESUMEN
Objective: To investigate the effects of selenium enriched yeast on antioxidative activities and immune functions in pregnant dairy cows. Methods: Twenty-four healthy Holstein-Friesian dairy cows were used for the experiment. All of them were pregnant as comfirmed by rectal palpation and divided into 4 groups, of which 3 were assigned for test groups(TI, T2, T3) and one served as control (C). Three different selenium (Se) sources namely Se-yeast (Sel Plex50, from Alltech ), mixture of Se compounds (70% Sel Plex 50 + 30% Na selenite ) and Na selenite were respectively supplemented to 3 test groups. Whole feeding experiment lasted for 168 days. During the experiment, the blood GSH-Px activity, serum Se concentration, erythrocyte superoxide dismutase(SOD) activity, malonaldehyde(MDA) level in serum, lymphocyte transformation rate and T cell count were determined. Results: Blood GSH-Px ,serum Se concentration and erythrocyte SOD activity,T1, T2 and T3 were higher (P