B. MICHIELS1, S. BABATOUNDE1, M. DAHOUDA1, S.L.W. CHABI1 and A. BULDGEN2
1 Département de Production Animale, Faculté des Sciences Agronomiques, Université Nationale du Bénin, Abomey-Calavi, Benin
2 Unité de Zootechnie, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
The experiment was conducted during the early (March–May) and the late (August–October) rainy seasons in 1997. A botanical inventory of forage selected by Djallonke sheep grazing Sudano-guinean savannas in central Benin was developed by observation and hand-plucking. Chemical composition of hand-plucked material was determined.
From March to May, just after the first rains, the forage selected had a high nutritive value (digestible crude protein of 64.7 g/kg DM and metabolisable energy of 9.2 MJ/kg DM). The most consumed material was young regrowth of Poaceae (Hyparrhenia sp., Loudetia arundinacea, Andropogon sp., Brachiaria sp., Heteropogon sp.) and Cyperaceae (Cyperus spp., Killynga squamulata). During the late rainy season, the frequencies of the consumed species were significantly different (P < 0.01). The proportion of Poaceae in the samples decreased, while the proportions of woody and gramineous dicotyledons increased. Despite the great selectivity of the sheep during this season, these changes greatly influenced the chemical composition and nutritive value of the diet. Digestible crude protein fell to 41.9 g/kg DM while fibre levels increased. Nevertheless, the metabolisable energy level still reached 9.1 MJ/kg DM.