Nutritive value of some Zagros Mountain rangeland species

This experiment was conducted to compare forage quality of 22 native species of The Zagros Mountain in Chaharmahal Bakhtiary province of Iran: Agropyron trichophorum, A. intermedium, Bromus tomentellus, Dactylis glomerata, Hordeum bulbosum, H. violaceum, Melica jaquemontii, Centaurea virgata, Coronilla varia, Fibigia suffruticosa, Galium verum, Lotus corniculatus, Medicago sativa, Onobrychis sativa, Plantago lanceolata, Sanguisorba minor, Silene chlorifolia, Trogopogon buphtalmodi, Lonicera nummulariifolia, Pterocephallus canus, Pterocephallus falcatus and Scropholania nervosa. Plant samples were collected from an exclosure about mid June, after-flowering stage. Forage quality was evaluated based on crude protein (CP), acid detergent fiber (ADF), dry matter digestibility (DMD) and metabolizable energy (ME) contents. For 10 species DMD was also measured using in situ procedure. There were significant differences between CP contents among legume (P < 0.05) and grass species. High ADF percentages were obtained in Centaurea virgata (47.4%) and Hordeum violaceum (47.3%). Low ADF contents were in Galium verum (27.2%) and Trogopogon talmoedi (27.3%). Hordeum violaceum exhibited the lowest DMD (47.6%), which was significantly different from other species except with Centaurea virgata. Metabolizable energy ranged from 1.69 for Hordeum violaceum to 2.36 Mcals kg−1 DM for Onobrychis sativa. Among three life forms of grasses, forbs, and shrubs, generally forbs species showed higher CP content (11.13%), lowest ADF (27.8%) and highest DMD (64.6%) obtained from shrubs. Positive correlation between CP and DMD, and negative correlation between ADF and DMD, and between CP and ADF were obtained. There was no significant difference between DMD estimated from equation and measured, using in situ procedure. Adequate nutrients are available in vegetation communities including the evaluated species.