Forage quality of three life forms of rangeland species in semi arid and semi humid regions indifferent phenological stages

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, phenolog ical 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 coro nilla varia) and two shrubs (salsola rigida and artemisia aucheri). samples were collected from two highland ranges of gachsar and yard avar. they were dried, grained and analyzed in laboratory . the results showed that forage quality indices values including crude protein (cp), acid deterg ent 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.