Seasonal trends in chemical composition and digestion of Dichanthium annulatum (Forssk.) Stapf

Nutritive value and rumen digestion of total plant, leaves and stems of Dichanthium annulatum were seasonally estimated. Male rumen fistulated Pelibuey x Rambouillet sheep, fed alfalfa hay, were used to incubate nylon bags. The crude protein (CP) content was higher in spring and lower in winter (P < 0.05). It was higher (P < 0.05) in leaves than stems. The cell wall (CW) and its components (hemicellulose, cellulose), insoluble ash and lignin were lower (P < 0.05) in spring and higher in winter and were higher (P > 0.05) in stems than in leaves. Dry matter, CP and CW of D. annulatum were digested, by rumen microbes in sheep, to a greater (P < 0.05) extent during spring and than in winter. Higher (P < 0.05) nutrient digestion was observed in leaves than in stems. In general, during spring mineral contents were higher and lower in winter. During spring when precipitation was high (417 mm out of 613 mm), nutrient content was higher than that in other seasons. Results suggest that except in winter, D. annulatum can be used in all seasons as a good source of nutrients for grazing beef cattle.