معرفي مهم ترين شاخص هاي تعيين ارزش غذايي گياهان مرتعي

An Introduction of the Most Important Factors in Range Species for the Determination of Nutrient Values

Information regarding forage nutrient value is important in grazing management of rangelands. For an investigation of variation in nutritive quality of forage in different climatic zones as well as in different phenological stages, five species were chosen For the study. Samples were collected randomly and dried for chemical analysis. Dry matter, ash, crude fat, crude fiber, crude energy, crude protein, acid detergent fiber, natural detergent fiber and minerals (Cu, Fe, Zn, Mn, Na, Ca and P) were measured by different analytical methods. Analysis of variance indicated that environmental conditions affect forage quality. Phenological stages caused more variation in forage quality than either climate or species. Nutrient qualities in forage in all species decreased from full flower to seed ripening stage. However, variations between either species or climate were not significant. Therefore in grazing management, variation of forage quality during growth stage should be taken into account. Based on correlation between investigated factors for classifications of forage quality, measurement of crude protein and acid detergent fiber are more important than the others.