Effect of Seasonal Variation on the Nutritional Quality of Key Herbaceous Species in Semi-arid Areas of Borana, Ethiopia

The nutritional quality of key herbaceous species was assessed across seven locations in Borana rangelands during the main rainy and dry seasons. Sixteen herbaceous species were evaluated for crude protein (CP), Neutral detergent fiber (NDF), Acid detergent fiber (ADF), Acid detergent lignin (ADL) and ash. The average CP content during the main rainy season was 8.8% with the highest value of 10.6%. During dry season the CP content of samples was generally below 6%. CP content was also varied significantly among individual species. Commelina africana accounted for the highest CP content, while Heteropogon contortus exhibited the lowest CP content. At the early stage of growth of plants, a low accumulation of NDF, ADF and ADL was recorded. Digitaria naghellensis accounted for the highest NDF, while Commelina africana had the highest ADL content. The ash content was lowered for most of the species with increased stage of maturity. The level of CP, NDF, ADF, ADL and ash in the species were greatly influenced by the study site. CP was negatively correlated with NDF, ADF, and ADL. It is suggested that the forages may be utilized at a proper stage to provide optimum nutrients for animals in the study area.