Bioconversion of sugarcane bagasse with Japanese koji by solid-state fermentation and its effects on nutritive value and preference in goats

Abstract

The effects of 3 different strains of Japanese koji (Aspergillus oryzae, A. sojae and A. awamori) in the solid-state fermentation (SSF) of sugarcane bagasse mixed with wheat bran on chemical composition, energy, in vivo digestibility and preference of the fermented bagasse feeds (FBF) in goats were investigated. Diets consisted of lucerne hay cube (basal diet) and unfermented bagasse feed (control), FBF with A. oryzae (O), FBF with A. sojae (S) or FBF with A. awamori (A), which were mixed in a total ration of 7:3 (w/w DM). Three Nubian does were fed each of the diets, i.e. control, O, S and A in the 4 consecutive periods for digestion trials (21-day each). The goats were also used for preference trials (30-min each) of O, S and A. The O was significantly higher in CP content than others (p<0.05). The crude fiber (CF), ADF and cellulose contents of control were significantly lower than those of other diets (p<0.05). The S had significantly higher CF digestibility than control (p<0.05), and it revealed the largest value of all. Digestibilities of NDF, ADF and cellulose in S were significantly higher than those of control (about 10, 18 and 18%, respectively, p<0.05). The DE of S was significantly higher than that of others (p<0.05), though there were no significant differences in DCP and TDN between control and S. The results of preference trials demonstrated that the average intake rate was not significantly different among diets, but O and S are likely to be preferable to A (p<0.1). It was concluded that the SSF of bagasse feeds by Japanese koji can improve the fiber digestion, especially NDF, ADF or cellulose in goats, and there is a marked effect in the feed containing A. sojae, which may lead to the improvement of DE.