1 Nutritive value of dominant rangeland plant species in Kaja and Chahno, Ferdows, South Khorasan

Rangelands, as one of the basic sources of production, have a special place in supplying livestock feed requirements. Considering the role of nutritive value characteristics on determining grazing capacity, the aim of this study was to compare nutritive value of Stipa barbata, Stipa capensis, Eryngium billardieri, Artemisia aucheri and Zygophyllum atriplicoides in rangelands of Kaja and Chahno ,Ferdows, South Khorasan province. For this purpose, in the representative area of ​​each plant type, 3 sites were selected and in each site, 10 replicates were sampled from the aerial parts of the plant species, in flowering stage. Then, nutrition value indices such as Crude Protein (CP), Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF), Dry Matter Digestibility (DMD), Metabolizable Energy (ME) and Digestible Energy (DE), as well as Sodium (Na), Calcium (Ca), Magnesium (Mg) and Potassium (K) in aerial parts of the plant species were determined by conventional methods in the laboratory. Analysis of variance (ANOVA) was used to compare the studied characteristics between the plant species. The results showed that there was a significant difference between the amount of CP, Na, K, Ca and Mg in the studied plant species (p≤0.01). Average CP, ADF and ME values were higher than those of critical limits to meet animal maintenance. Artemisia aucheri has the highest amount of Ca (2.5%) and Mg (0.88%) and Zygophyllum atriplicoides has the highest CP (18.64%) and K (1.03%), so it is the highest quality plant species in the rangelands of Kaja and Chahno, Ferdows.