Effect of different processing methods on the biochemical composition of water hyacinth and acceptability by WAD goats

Abstract

The limiting factor in the use of water hyacinth (WH) as a fodder is the high moisture content. Subjecting this water weed to various processing methods might reduce the moisture content to an appreciable level that will be tolerated by animals. Fresh samples of water hyacinth harvested from lagoon water body in Ogun State were processed into wilted, ensiled, sun-cured. Two experiments were conducted. Experiment 1 involved the determination of nutrient composition (Dry matter, Crude protein, Crude fibre Ash, Neutral detergent fibre and Acid detergent fibre), mineral content(macro and micro minerals) and secondary metabolites (spot test analysis of (saponin, phenol and steroid) of fresh and processed WH. In experiment II, the fresh and processed WH were fed to eight WAD goats in a cefetaria feeding trial to determine the Coefficient of Preference (COP) ofall forms of water hyacinth. Results revealed that, the nutrient composition was influenced by processing methods except for the ash content. The sun-cured WH contained more dry matter (89.30 g/100g DM), while the lowest dry matter (8.22 g/100g DM) was recorded for fresh WH. However, ensiled WH contained more crude protein (16.23 g/100g DM) than other forms of WH, the lowest CP (10.42 g/100gDM) was recorded for fresh WH (DBG has some protein in it and it added to the water hyacinth, hence the raised CP content of ensiled WH). However, the neutral detergent fibre ranged from 55.20 to66.25 g/100g DM in ensiled and sun-cured respectively.The mineral content of all forms of WH were similar. Qualitative evaluation of saponin, phenol and steroid showed that all forms of WH contained tannins and steroids; saponin was found but declared negative due to height of the form. The result of COP,showed thatthefresh WH (0.74) was rejected, while all processed WH were acceptable to the animals.However,the ensiled WH (1.40) was most preferred. It is concluded that processing methods can improve the nutrient composition of WH and also the preference by animals.