Assessment of Environmental Impact and the Nutritive Value of Water Hyacinth (Eichhornia Crassipes Mart. Solms-Laubach) in Ruminant Nutrition in Nigeria

Abstract

Two experiments were conducted to investigate the environmental impact and nutritive value of water hyacinth (WH) in ruminant nutrition in Nigeria. In the first experiment, biomass yield, chemical composition, secondary metabolites and mineral content of WH harvested during the four sub seasons of the year were determined. The second experiment assessed the nutritive value of WH using in vitro gas production to predict the potential degradability (a+b), insoluble degradable fraction (b), rate of gas production (c), metabolizable energy (ME), short chain fatty acids (SCFA) and methane (CH₄). Biomass yield (ton/ha/year) of WH was highest during the late dry (LD) season which was estimated at 33.24 ton DM/ha/yr at 7 – 8% DM content. Seasonal variations had no significant effect on the chemical composition; the CP was highest during the late dry season (10.42%). However DM was influenced (P<0.05) by seasonal changes. WH contained tannins and steroids; saponin was declared negative due to the method used. Macro and micro mineral values are high, but not significant. ME, OMD and SCFA also were not influenced by season changes, although, highest ME, OMD and SCFA was obtained during the LD season (15.62 MJ/kg DM, 49.20% and 0.57mmol) respectively. Same trend was observed for gas production characteristics. However rate of substrate fermentation (c) differed (P<0.05) significantly, ranging from 0.04 to 0.06 (in late rain to late dry) respectively. The result showed that WH is available all year round and could provide nutrients to be utilized as fodder for ruminant especially during the dry season.