Botanical composition and nutritive value of forage consumed by sheep during the rainy season in a Sudano guinean savanna (central Benin)

The experiment was conducted during the early (March-May) and the late (Aug ust-October) rainy seasons in 1997. A botanical inventory of forage selecte d by Djallonke sheep grazing Sudano-guinean savannas in central Benin was d eveloped by observation and hand-plucking. Chemical composition of hand-plu cked material was determined. From March to May, just after the first rains, the forage selected had a hi gh nutritive value (digestible crude protein of 64.7 g/kg DM and metabolisa ble energy of 9.2 MJ/kg DM). The most consumed material was young regrowth of Poaceae (Hyparrhenia sp., Loudetia arundinacea, Andropogon sp., Brachiar ia sp., Heteropogon sp.) and Cyperaceae (Cyperus spp., Killynga squamulata) . During the late rainy season, the frequencies of the consumed species wer e significantly different (P < 0.01). The proportion of Poaceae in the samp les decreased, while the proportions of woody and gramineous dicotyledons i ncreased. Despite the great selectivity of the sheep during this season, th ese changes greatly influenced the chemical composition and nutritive value of the diet. Digestible crude protein fell to 41.9 g/kg DM while fibre lev els increased. Nevertheless, the metabolisable energy level still reached 9 .1 MJ/kg DM.