Effects of Varieties of Indigenous Bamboos (Oxytenanthera abyssinica and Yushania alpina), their Morphological Fractions and Season of Harvest on Chemical Composition, In Vitro and In Sacco Degradability in Ethiopia

Abstract

Chemical composition and nutritive values of lowland bamboo (LB) (Oxytenanthera abyssinica), red highland bamboo (RHB) and black highland bamboo (BHB) (Yushania alpina) varieties (V) harvested during wet and dry seasons were determined in this study. Morphological fractions of the varieties such as leaves, twigs and foliage were evaluatedo for the purpose. The chemical compositions were determined according to the standard procedures. IVDMD was determine using two-stage rumen inoculum-pepsin method. In sacco N degradability were evaluated by the nylon bag technique using three ruminally fistulated Boran x Holstein Friesian steers. The result of the study revealed that leaves collected from RHB had significantly (P<0.001) higher CP content (209 g/kg DM) than twigs and foliage of other two verities of bamboo. Significantly (P<0.001) higher NDF and ADF contents were recorded for highland bamboo varieties in the dry season which can be implicated for lower ME in the variety. Among the MF, only twig consisted smallest CP content (62 g/kg DM). Leaf collected from LB had significantly (P<0.001) higher IVDMD (447 g/kg) than the leaf of HB varieties (338 and 344 g/kg). The LB leaves and foliages harvested in the wet season had significantly (P<0.001) higher N degradability (69.9-88.3 g/kg DM) than the HB varieties. Likewise, the rapidly soluble, slowly degradable and effective degradability fractions of N were higher in LB leaves and foliages harvested in the wet season than in the leaf of HB varieties. The results of this study suggested the existence of variation on chemical composition and degradability among bamboo verities, morphological fractions and harvesting seasons. It was recommended that these variations among the component of the plant need to be considered for appropriate utilization of bamboo plants as a feed resource for ruminant.