بررسي تغييرات كيفيت علوفه گونه هاي مرتعي در مناطق مختلف آب و هوايي

A Study of Variation of Forage Quality of Range Species at Different Phenological Stages and in Different Climatic Zones

Information regarding forage quality and its variation in different climatic zones and at various phenological stages can help a range manager to determine daily animal requirement which in turn is essential in an evaluation of grazing capacity.In order to determine forage quality, five species of vegetation namely; Agropyron tauri, Agropyron trichophorum, Bromus tomentellus, Festuca ovina and Hordeum bulbosum were collected from 18 vegetation communities of 8 climate zones and at three phenological stages of vegetative, flowering and seed ripening. Plant samples were analysed to determine N prcentage as well as ADF. Metabolizable Eenergy was assessed as a forage quality factor. Variance analysis was applied to data. Results indicated that Metabolizable Energy is significantly affected by species, phenological stage as well as climatic zone.