Professor, Faculty of Natural Resources, University of Tehran, Iran
Faculty member of Islamic Azad University, Azadshahr branch, Iran
Asociate professor, Faculty of Natural Resources, University of Tehran, Iran
Professor, Faculty of Agriculture, University of Tehran, Iran
For determination of grazing capacity, information of forage quality is essential which is influenced by various factors. The main objective of this research was investigation on effects of species, phenological stages, and life form on values of forage quality indices of six range species. Species were two grasses (Bromus tomentellus and Dactylis glomerata), two forbs (Ferula ovina and Coronilla varia) and two shrubs (Salsola rigida and Artemisia aucheri). Samples were collected from two highland ranges of Gachsar and Vard Avar. They were dried, grained and analyzed in Laboratory. The results showed that forage quality indices values including crude protein (CP), acid detergent fiber (ADF), dry matter digestibility (DMD) and metabolizable energy (ME) were significantly differed among species, phenological stages, and life forms (P<0.01). For all species CP, DMD, and Me decreased and ADF increased with plant growth development. Considering forage quality indices values among six species, C. varia had highest forage quality. Among life forms, forbs, higher forage quality obtained from forbs. In terms of growth stage, vegetative growth stage had better forage quality.