Crude Protein, Phosphorus, Common Salt, and Mineral Composition of Range Plants and their Nutritive Value for Grazing Ruminants in Southern Iran

The present study was conducted in a dry region to evaluate 1) the crude protein, phosphorus, common salt, and mineral composition of different range plants and 2) their value for grazing ruminants such as cattle, sheep, and goats. The research region was divided into five separate sites with vegetation cover of the range plants Atriplex lentiformis, A. nummularia, and A. halimus (all newly introduced species) and A. leucoclada and Salsola rigida (both native species). Six separate samples of the aerial parts were taken at random and analyzed for determination of their total nitrogen (N), phosphorus (P), sodium (Na), chloride (Cl), and mineral composition. The crude protein content ranged from 8.23% for S. rigida to 14.57% for A. nummularia. Except for P content, Na and Cl of the all tested plants were well more than the critical levels and may be considered adequate for grazing ruminants. However, all of the tested plants contained P levels below the critical concentration, and thus supplementation of P seems to be necessary in the research region. The results suggest that Ca, K, and Na levels may be considered adequate for grazing ruminants; however, supplementation of Mg would seem to be necessary in the research region in Dadin area, especially when A. leucoclada, A. nummularia, and S. rigida species are the main sources of animal food. Because iron (Fe), manganese (Mn), and copper (Cu) concentrations of the tested plants are greater than the critical levels, they may be considered to be adequate for grazing ruminants; however, supplementaion of zinc (Zn), especially for A. leucoclada, S. rigida, and A. lentiformis, would seem to be necessary in the research region. The total of mineral concentrations of the tested plants suggested that, from a nutritional point of view, the three new introduced species are richer than the two native species.