Copper Supplementation of Young Cattle Grazing Improved Meadow Pastures in Southeastern Oregon

Abstract

Yearling cattle grazing improved, tall fescue-legume, meadow pastures showed signs of copper deficiency. Copper supplemented as injected Cuprin or as CuSO4-salt mix reduced the copper deficiency as expressed by blood plasma analyses and animal gains. Yearlings receiving Cu gained 0.10-0.31 kg/hd/day more than the checks. The methods of supplying the Cu were equally effective, but injections raised large lumps on some animals. The interrelationship of Cu and Mo and their relative concentrations in forage are important considerations in livestock nutrition. The forages grown on meadow soils in southeastern Oregon can cause signs that are associated with Cu deficiency in cattle. The sedges and rushes, dominant species in flood meadows, are less likely than grasses and legumes to cause Cu deficiencies because of favorable Cu/Mo ratios. Of the species tested, tall fescue and white clover were most likely to cause deficiencies because of their relatively high concentrations of Mo.