Tropical crop and crop by-product additives can improve the quality of taro leaf (Colocasia esculenta) silage

Abstract

SUMMARYThe nutritive value of taro leaf (Colocasia esculenta) silage, with or without various crop or crop byproducts as additives, was evaluated in two experiments in Western Samoa in 1988 and 1989. In Experiment 1, laboratory silos were used to assess the quality of eight taro leaf silages which were either ensiled fresh or wilted overnight. Taro leaf ensiled alone was poorly preserved with a pH of 5·4 and high concentrations of ammonia-N and volatile fatty acids. In contrast, silages with crop byproduct additives rich in water soluble carbohydrates (WSC), mainly molasses, ripe banana or papaya pulp, were of high quality with pH levels ofc. 4 and low concentrations of volatiles. Copra meal, although low in WSC, was able to produce a satisfactory silage when added to taro leaf through its ability to restrict fermentation.Despite only a small increase (14·2%) in silage dry matter (DM) content, wilting of taro leaves resulted in silage of significantly higher quality than that made from fresh leaves. Most of the benefit of wilting was attributed to better fermentation conditions rather than a restricted fermentation.Two of the better silages from Experiment 1, taro/molasses and taro/banana, were prepared on a larger scale in earth pits and fed to goats in a second experiment. Both silages were highly palatable and digestible; DM intakes of 47 and 63 g/kg W0·75per day and organic matter digestibilities of 69·0 and 74·9% were recorded for the banana and molasses silages, respectively.It was concluded that taro leaf is a suitable forage for ensilage, and when combined with additives rich in WSC, a forage of high nutritive value can be produced.