Abstract
The mineral status of pastures from 13 farms in the eastern region of Uganda was investigated together with the mineral content of plasma from cattle on the farms. Nitrogen sodium, potassium, calcium, magnesium, pbosphorus, sulphur, manganese, copper and zinc were determined in the pasture and calcium, magnesium and phosphorus in bovine plasma. Leafy material was collected from the dominant pasture species which included: Chloris gayana, Hyparrhenia rufa, Panicum maximum, Pennisetum purpureum, Centrosema pubescens and Stylosanthes gracilis. The pastures contained adequate amounts of nitrogen, potassium, magnesium and sulphur, and where legumes were present the pasture supplied adequate amounts of calcium and manganese for a 500 kg cow giving 10 kg milk per day. Sodium and zinc were deficient and supplementation of these two elements was recommended. The amount of phosphorus was marginal and some supplementation of this element was considered necessary. Copper supplementation was not considered advisable until definite copper deficiency symptoms bad been reported. Magnesium, although generally sufficient at the present time, may become deficient with increased use of potassium fertilizer .
