Effects of moisture control, addition of glucose, inoculation of lactic acid bacteria and crushing process on the fermentation quality of rice grain silage

To identify the best ensiling process and moisture content for rice grain silage, we determined the effects of additive (i.e. no additive, glucose additive or lactic acid bacteria [LAB] inoculation), crushing process (non-crushing or crushing) and moisture control (none [13.6%], 20.0, 27.5, 35.0, 42.5 or 50.0% moisture content [in fresh matter, FM]) on rough rice and brown rice. Forage rice harvested at the fully ripe stage was ensiled in small-scale experiments, and the silage was stored for 60 days. Regardless of the use of additives or LAB inoculation, the pH values tended to decrease with increasing moisture content. LAB inoculation and crushing resulted in low pH values, low butyric acid contents, low ethanol contents and high lactic acid contents, and the lactic acid content increased to more than 2.0% in FM at moisture contents of 27.5% and higher. The parameters of fermentation quality (pH, lactic acid, butyric acid, volatile basic nitrogen and ethanol content) were affected by not only the main effect of additive, crushing process and moisture control but also two-way or three-way interaction effects. LAB inoculation and crushing improved the lactic acid fermentation under lower moisture conditions, that is, 27.5% moisture content. In both rough rice and brown rice, we suggest that the appropriate pretreatment is the combined use of LAB inoculation, crushing process and controlling 27.5% moisture content.