Nutritive Value of dominant rangeplant. In Chaharmahal & Bakhtiari Province of (IRAN, I.R.) phase I. Determination of chemical composition and

In order to determine the chemical composition and in vitro digestibility range plants, samples of ten species (Agropyron intermedium , Bromus tomentellus, Hordeum bulbosum, Cosinia bakhtiarica, Scariolla orientalis, Vida variabilis, Astragalus spp. , Medicago sativa, Prangus uloptera and Sanguisorba minor ), which were most dominant range plants in the province, were collected at growing, blooming and Seedling stage. From different controled stations for three years in 1376-1380. All samples were chemically analysed for CP, EE, NDF, ADF, CF, GE, Ash, Ca, P, Na, K, Mg, Cl, Cu, Fe, Mn, Zn and digestibility was determined in vitro and energy was determined using of calorie meter bomb. Total mean of cp for the above plants was 13.7, 13.3, 15.2, 13.5, 11.4, 9.1, 21.8, 22.1, 23, 13.7 and 14.3 percent respectively at growing, 8.0, 6.9, 8.4, 5.8, 5.2, 20.4, 13.9, 15.3, 9.4 and 10 percent, respectively at flowering and 4.1,3.6,2.9,4.8,3.4, 13.1, 10.1, 12.7,6.9 and 8 percent, respectively at seedling stages. The average ofDDM was, 50.6, 49.1, 54.6, 53.2, 58.6, 54.6, 56.2, 53.2, 60.7 and 42.8 percent, respectively at growing, 50.2, 45.3, 49.9, 45.4, 48.3, 65.9, 47.5, 48.3, 58.6 and 47.2 percent, respectively at flowering and 46.4, 41.7, 45.6, 42.8, 45.3, 57.5, 50.9, 46.3, 54.6 and 49.7 percent, respectively at seedling stages. The results showed the highest and lowest amount of CP were 18.5 and 6.67 percent for Vida variabilis and Scariolla orientalis respectively. The highest EE (4.4) and lowest (1.98) percent was for Prangus uloptera and Astragalus spp. respectively. The maximum NDF was due to Bromus tomentellus (72.6%) and the Minimum to Prangus uloptera (40.1%). The highest percentage of ADF was 49.4 and the lowest was 27.9, which observed in Cosinia bakhtiarica and Vida variabilis respectively. Also the highest CF (41.9%) and lowest (24.1%) was determined in Cosinia bakhtiarica and Prangus uloptera respectively. The minimum of GE was 4 Meal/kg DM which found in Prangus uloptera and Sanguisorba minor and the maximum was 4.3 Meal/kg DM in Cosinia bakhtiarica and Agropyron intermedium. The highest Ash content (10.8%) and lowest (6.7%) was seen in Prangus uloptera, and Scariolla orientalis respectively. The dry mater digestibility (DDM). was maximum in Vida Variabilis (59.3%) and minimum in Bromus tomentellus (45.4%). The highest and lowest organic mater digestibility (DOM) was 66.7% and 52.2% which found in Prangus uloptera and Bromus tomentellus respectively. As the plants matured percentage of CP, DDM, DOM decreased and NDF, ADF, CF, EE increased. The mineral status showed that all of the species was a bove in Ca than critical value for ruminant except Hordeum bolbosum, but content of P was lower than critical value required for ruminant. All species was lower than critical in Na content, K content was greater than the requirements of ruminant, The Mg content in family of gramineae and species of Cosinia bakhtiarica were also lower than critical value required for ruminants. The cholorin content was uper than requirement of ruminant in all plant species, Than we must controlled the rat of Na and K content of range plant usually. The concentration of copper in most cases was lower than critical point required for ruminant, but Iron was much enough for ruminant in all species. Except for the compositeae Family Mn content was in a normal range. Deficiency of Zn except for Vida Variabilis in vegitative and flowering stage was observed for other species. According to the resultes, effect of plant species and phases of phenology in the status of plant minerals was probably more important than other factors, such as yearling samples, soil and climate