Advantages of solid fermentation state with Pleurotus sapidus in sugar cane silage

In this study the effect of Pleurotus sapidus used in sugar cane in solid state fermentation and then after 24 d of silage, was evaluated in nutrition quality, fermentation and ruminal digestibility. Whole sugar cane (CAI) was initially aerobically fermented for 48 h (CIF), and then used as a substrate inoculated with Pleurotus sapidus and additionally fermented for 15 d (FSP15). Different mixtures were prepared with CAI and two amounts (10 and 20%) of FSP15, so three treatments were considered: CAI+10%FSP15 y CAI+20%FSP15. Diverse variable were evaluated, including bromatologic analysis, fermentation patterns and digestibility, for CAI, CIF, FSP15 and silage mixtures at times 0 and 24 d. Protein content in CAI increased 1.9% after 15 d of fermentation with Pleurotus sapidus (FSP15). When 2 different portions of this matter were mixed (10 and 20% as part of the mixture), percentage of DIVMS increased from 64.8 up to 70.1% DM after 24 d of silage, although no significant difference was observed between these two amounts in such mixtures. During ruminal fermentation of raw CAI gas production was higher (p<0.05) (260.6 ml/500 mg DM) due to a high content of soluble sugars, in comparison to those values found for the sugar cane silages added with 10 or 20% of FSP15 (233.7 and 233.3 ml/500 mg DM), respectively. This study showed that addition of FSP15 to CAI, after 24 d of ensiling, reduced the lactate and ammonium proportion with no effect on final pH in those silages. Maximal gas production during ruminal fermentation and digestibility increased in all treatments added with FSP15. This work contributes with the use whole sugar cane as a substrate for the growth of lignocellulosic fungi, which in turns can be mixed and ensilaged for ruminant feed in tropical zone with high sugar cane production.