Chemical Composition and In Vitro Digestibility of Some Range Species in Rangelands of Chaharmahal and Bakhtiari Province, Iran

Abstract

Five common range forage including Agropyron intermedium, Bromus<br />tomentellus, Hordeum bulbosum, Cousinia bakhtiarica and Scariolla orientalis, were<br />sampled during three phenological stages, from controlled rangeland stations over five<br />locations in Chaharmahal and Bakhtiari province, Iran. All samples were chemically<br />analyzed for Crude Protein (CP%), in vitro Dry Matter Digestibility (DMD), Organic<br />Mater Digestibility (OMD), Ether Extract (EE), Crude Fiber (CF), total Ash, Neutral<br />Detergent Fiber (NDF) and Acid Dtergent Fiber (ADF). Results for Crude Protein (CP%)<br />showed significant differences between phenological stages in all of species. Maximum CP<br />(15.2%) was found in vegetation stage of Hordeum bulbosum and the minimum (2.9%)<br />was in seed ripening stage. The CF% was significantly different between phenological<br />stages as well as the species. The minimum and maximum values of CF% were found in<br />Agropyron intermedium in Coosinia bakhtiarica, respectively. Similarly, the minimum<br />values of NDF and ADF were found in vegetative stage of Scariolla orientalis and<br />Agropyron intermedium respectively, but the maximum values were obtained in seed<br />ripening stage of Hordeum bulbosum and Cousinia bakhtiarica. The DMD and OMD%<br />showed slightly reduction passing from vegetation to seed ripening stage in most of the<br />species. The highest DMD and OMD% had been observed in vegetation stage of Scariolla<br />orientalis and the lowest were in Bromus tomentellus. It can be concluded that in the early<br />stage of growth, the quality of forage in range species is adequate for livestock<br />production but during that stage, the greatest problem is its lower quantity. By progress of<br />the vegetation stage toward the seed ripening stage, the nutritive value of all species<br />decreased thus grazing animals oppose to nutrient deficiencies.