Modulation of Bovine Mononuclear Cell Proliferation and Cytokine Production by Dietary Copper Insufficiency

Studies were undertaken to determine immunological effects of subclinical copper deficiency in the bovine. Ten primigravid Holstein heifers were maintained on a basal (6-7 ppm Cu; n = 5 heifers) or copper-supplemented (20 ppm; n = 5 heifers) diet beginning 84 d prepartum. Blood mononuclear cells were isolated at approximately 90 d of lactation. Mononuclear cells were evaluated for proliferative capacity and in vitro cytokine production. The dietary protocol utilized induced significant (p < 0.05) decreases in liver copper stores in unsupplemented heifers without major effects on blood indicators of copper status. Mononuclear cell proliferation was not significantly affected by copper status. Mononuclear cells isolated from copper-supplemented heifers produced significantly (P < 0.05) more interferon in vitro than cells from copper-insufficient animals. Supplementation of copper to previously copper-insufficient animals reversed each of these trends and improved in vitro interleukin-2 production. ...