サイレージ調製

In ensiling forages, the increase in the activity of butyric acid bacteria is the most effective cause to lower fermentation quality. The objective of this study was to investigate the relationship between silage fermentation quality and the number of spores of Clostridium counted using two different methods. Forage oat (Avena sativa L.) was cut and treated with either 1% (fresh weight basis of material) glucose or 5% ethanol or O.5% formic acid or wilting without additives. ln each treatment materials were ensiled into a laboratory silo and stored at 200C for 1, 3, 5, 7 or 14 days. There was one more treatment without additives or wilting, where forage oat was ensiled and stored at 35 ℃ for the same periods. Thus, there were six treatments including control. After the silos were opened the samples of silages were analyzed for fermentation quality； pH, organic acids and volatile basic nitrogen. The number of spores of ClosCridium was counted with two methods； dilution plate method and most probable number method. Silages showed good fermentation quality in almost all treatments with low values of pH and volatile basic nitrogen, and no butyric acid. The number of spores counted using dilution plate method showed similar changes but larger values compared to most probable number method. There was a significantly negative correlation between pH of silages and the number of spores when counted with dilution plate method (r＝-0.605, p<0.OOI).