Chemical Composition, Ruminal Dry Matter, Crude Protein andCell Wall Degradation Kinetics of Pasture Forages Dominant in the West Provinces of Iran

Abstract

The objectives of this study were to determine and compare the chemical composition and ruminal degradability of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of ten pasture forage species dominant in the west provinces of Iran. Duplicate nylon bags of pasture samples were suspended in the rumen of four wethers for up to 96 h. The chemical composition of forages varied from 54 to 212 g/kg DM for CP, 239 to 638 g/kg DM for NDF, 190 to 378 g/kg DM for ADF and 60 to 108 g/kg DM for ash. The effective DM degradability at rumen outflow rate of 0.05/h was different (P<0.05) between forages and varied from 307 g/kg for <em>Festuca ovina</em> to 679 g/kg for <em>Prangus ferulacea</em>. The lowest CP degradability was for <em>Festuca ovina</em> (402 g/kg) and the highest for <em>Bromus tomentellus</em> (760 g/kg). The lowest NDF and the highest ADF degradability were for <em>Hordeum bulbosum</em> and <em>Prangus ferulacea</em>, respectively. The results of this study showed that the rate and extent of ruminal CP and cell wall degradation were different among forages, therefore must be considered as a main parameter in ration formulation of grazing ruminants.