Browsing Journal of Range Management, Volume 35, Number 4 (July 1982) by Authors
Copper Supplementation of Young Cattle Grazing Improved Meadow Pastures in Southeastern OregonGomm, F. B.; Weswig, P. H.; Raleigh, R. J. (Society for Range Management, 1982-07-01)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.
Meadow Forage Production as Influenced by Fertilization in a Dry YearGomm, F. B. (Society for Range Management, 1982-07-01)During drought years, stream flow is often insufficient to irrigate normally flooded native meadows. Herbage production of the meadow is reduced, haying operations are suspended, and the available forage is grazed by cattle. Fertilization of meadows in eastern Oregon is done in the late fall or early spring before the availability of irrigation water for the following growing season is known. This study was initiated in 1977, following a severe winter drought, to determine the effect of fertilizing meadows in a dry year. Urea fertilizer was applied at 13 rates (0 to 745 kg N/ha). Maximum forage production of 1,000 kg/ha occurred about mid-July for the check treatment. Production was not increased at fertilizer rates of 0 to 50 kg N/ha, but were increased up to 1,600 kg at fertilizer rates of 95 to 745 kg N/ha. Crude protein concentrations in the forage were similar to those measured in years of normal rainfall. Herbage NO3- N levels were considered nontoxic at fertilizer rates less than 540 kg N/ha. It appears that during years of low precipitation, with customary rates of fertilization (90-110 kg N/ha), forage production will be increased slightly, forage quality will be about normal, and the danger of nitrate poisoning will be nil.