Effect of Fermentation Using Different Microorganisms on Nutritive Values of Fresh and Dry Cassava Root

Abstract

Background and Objective: Cassava (Manihot esculenta Crantz) is widely grown in sub-tropical and tropical areas, producing roots as an energy source containing high soluble carbohydrate but low in crude protein.The process of protein enrichment of animal feed using microorganisms in a semi-solid culture to improve the nutritional value of ruminants feed has been considered.This study aimed to investigate the effect of microorganism fermentation on nutritional values of cassava products and in vitro rumen fermentation and digestibility.Materials and Methods: The experimental design was a 2×4 factorial arrangement in a completely randomized design.Factor A was two types of cassava root (fresh cassava root (FC) and cassava chip (CC)) and factor B was four sources of microorganism inclusion [no microorganism (No), Yeast (Y), effective microorganism (EM) and Yeast+EM (EMY)), respectively.Results: The results found that crude protein of cassava root was dramatically increased by Y and EM fermentation and the highest was found in CC (p<0.05).The gas kinetics, cumulative gas production (96 h) and in vitro dry matter and organic matter digestibility were enhanced by Y and EM fermentation (p<0.05),especially in CC group.Moreover, Y and EM could increase concentration of volatile fatty acids and ammonianitrogen while reduced methane production (p<0.05).Ruminal bacteria and fungi were increased whereas protozoa population was reduced by Y and EM fermentation.Conclusion: In conclusion, Y and EM fermentation could improve nutritional values of cassava products and enhance nutritional digestibility, rumen fermentation efficiency while decrease protozoa and methane production.However, further researches in feeding trial could be conducted.