EFFECTS OF IN-VITRO SUPPLEMENTATION OF BOVINE MAMMARY-GLAND MACROPHAGES AND PERIPHERAL-BLOOD LYMPHOCYTES WITH ALPHA-TOCOPHEROL AND SODIUM SELENITE - IMPLICATIONS FOR UDDER DEFENSES

Vitamin E and selenium have been observed to enhance the functions of bovine mammary gland macrophages and peripheral blood lymphocytes. In vitro supplementation with these compounds enhanced the production of neutrophil chemotaxins by macrophages stimulated with opsonised Staphy lococcus aureus. Supplementation also enhanced the proliferation of pe ripheral blood lymphocytes in response to stimulation with concanavali n A but not to phytohaemagglutinin or pokeweed mitogen. There was no e vidence of additive or synergistic effects of vitamin E and selenium. Results suggest that supplementation of cattle may optimise resistance to mastitis by enhancing the functions of resident macrophage and lym phocyte populations.