Title: An evaluation of nutritive value of water hyacinth (Eichhornia crassipes Mart. Solms-Laubach) harvested from different water sources as animal feed
Abstract: One of the major problems of water ways in Nigeria is the rapid infestation of water hyacinth causing environmental hazard. Water hyacinth (WH), may be useful as sustaining feed source for livestock especially ruminants. The objective of this study was to evaluate the potential of water hyacinth (WH) for ruminant nutrition. The chemical composition and spot test analysis for saponin, tannin and steroids was determined. In vitro gas production of WH collected from different water sources (DWS) during dry season was carried out under a 24 h in vitro gas fermentation in order to estimate the Metabolizable energy (ME), Organic matter digestibility (OMD) and Short Chain Fatty Acids (SCFA). Methane production was estimated at 24 h post incubation.
The crude protein, ether extract, and ash varied significantly (P<0.05) by different sources of WH. The CP varied from 10.3 to 10.4 g/100g DM. The dry matter, crude fibre, acid detergent fibre and neutral detergent fibre were not significantly affected by different water sources. Qualitative evaluation of the secondary metabolites showed that WH from all different water sources contained tannins and steroids; saponin was found but declared negative due to the qualitative method used. Plants from all DWS were rich in minerals.The cumulative gas produced at 24 h was 19.3, 18.2, 16.0 and 18.0 ml/200 mg DM for DWS 1, 2, 3 and 4 respectively. The CH4 production differed significantly (p<0.05) with water source 2 recording the highest value of 5.0 ml and the lowest value 2.7 ml was recorded for water source 3. The ME, OMD and SCFA also varied significantly (p<0.05) ranging from 5.0 to 5.5 MJ/Kg DM, 44.6 to 50.4 % and 0.437 to 0.522 umol respectively. The nutritive composition, secondary metabolites and in vitro gas production parameters showed a potentially high CP and energy available in water hyacinth, suggesting its possibility of being utilized for ruminant production in the tropics. [Mako A A, Babayemi O J and Akinsoyinu A O 2011: An evaluation of nutritive value of water hyacinth (Eichhornia crassipes Mart. Solms-Laubach) harvested from different water sources as animal feed. Livestock Research for Rural Development. Volume 23, Article #106. Retrieved June 27]
Key words: Composition, Eichhornia crassipes, in vitro gas production, secondary metabolites, water source