Effects of dietary supplements of selenium, vitamin E or combinations of the two on antibody responses of broilers.

1. The effects of selenium and vitamin E supplementation on some immune parameters were investigated in broilers. 2. Broiler chicks were fed on maize-soybean diets with different concentrations of vitamin E (0-200 mg/kg) and selenium (0-0.2 mg/kg diet) either alone or in combinations from 1 to 42 d of age. 3. Chicks were immunised against Newcastle disease virus (NDV) vaccine at 21 d of age and haemagglutination inhibition (HI) titres were determined after 10 d. 4. Chicks receiving supplements of 200 mg vitamin E/kg and 0.2 mg selenium/kg produced significantly higher HI antibody titres. This was associated with an increased serum concentration of total immunoglobulins and circulatory immune complexes. 5. The chicks given 200 mg vitamin E/kg and 0.2 mg selenium/kg had significantly heavier spleen and bursa. 6. These results suggested that vitamin E and selenium have synergistic effects on immune responses.