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

Abstract

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.

Farm‐scale method for producing high‐quality rice grain silage

“…In our previous study with pouch silos, rice grain silage with no additives resulted in ethanol production (Inoue et al . ). However, in the same study, we found that inoculation with LAB combined with the crushing process and adjustment of FM moisture content above 27.5% reduced ethanol production and enhanced lactic acid fermentation.…”

“…This confirms at the farm scale the results of our previous laboratory study, which suggested that the optimal pretreatment for ensiling rice grain is crushing, LAB inoculation and adjusting the moisture content of FM to about 30% (Inoue et al . ). After 1 year of storage, the lactic acid content had decreased, but the pH was stable at the desired level.…”

“…; Inoue et al . , ). In a previous study using vacuum‐packed pouch silos, we reported that the optimal pretreatment for rice grain silage was inoculation with lactic acid bacteria (LAB), crushing and adjusting the moisture content of the fresh matter (FM) to no less than 27.5% (Inoue et al .…”

“…In a previous study using vacuum‐packed pouch silos, we reported that the optimal pretreatment for rice grain silage was inoculation with lactic acid bacteria (LAB), crushing and adjusting the moisture content of the fresh matter (FM) to no less than 27.5% (Inoue et al . ). However, to our knowledge, no reports have been published on the fermentation quality of rice grain silage at the farm scale.…”

“…Rice grain silage has been researched for its potential to provide a low-cost storage method of feed rice that does not require a drying process (Uegaki et al 2010;Inoue et al 2012Inoue et al , 2013. In a previous study using vacuum-packed pouch silos, we reported that the optimal pretreatment for rice grain silage was inoculation with lactic acid bacteria (LAB), crushing and adjusting the moisture content of the fresh matter (FM) to no less than 27.5% (Inoue et al 2013). However, to our knowledge, no reports have been published on the fermentation quality of rice grain silage at the farm scale.…”