Effects of in vitro supplementation of bovine mammary gland macrophages and peripheral blood lymphocytes with α-tocopherol and sodium selenite: implications for udder defences

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 Staphylococcus aureus. Supplementation also enhanced the proliferation of peripheral blood lymphocytes in response to stimulation with concanavalin A but not to phytohaemagglutinin or pokeweed mitogen. There was no evidence 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 lymphocyte populations.