Nutritive evaluation and acceptability of two aquatic weeds (Eichhornia crassipes and Acroceras zizanioides) by West African dwarf goats

Abstract

Aquatic weeds are plants which grow and reproduce in rivers, streams, brooks, swamps and dams without agronomic care. They have potentials as forage for ruminants. The chemical composition, forage acceptability, secondary metabolites and N- balance of Eichhornia crassipes (EC) and Acroceras zizanioides (AZ) were studied using West African Dwarf goats. The effect of rainy and dry seasons in EC was not noticed for dry matter, crude protein, ether extract, crude fibre and ash. Crude protein content was highest (14.40%) in the leaf but least (7.04%) in the stem and this was contrary for crude fibre. Fresh EC and AZ were richer in crude protein (11.80 and 23.60%) respectively, but lower in dry matter (7.70 and 18.72%) than the dried form. AZ contained more crude protein (23.6%) and was more preferred in the fresh and dried forms by goats than any of the presented form of EC. The two water weeds contained tannin, phenol and saponin at non-toxic levels. Dry matter intake (DMI) increased at 20 and 40% supplementation than grass alone, but decreased with 100% AZ. N-balance and N-retention by goats was positive in AZ composed forages, but negative for AZ alone. The results revealed that EC and AZ are potential sources of nutrients for ruminants. Key words: Aquatic plant, chemical composition, forage acceptability, secondary metabolites, nitrogen balance.