Abstract
The aim of this study was to determine the optimal number of wrapping film layers and optimal moisture content for preserving the quality of low moisture round bale silage. Timothy silage was used in the experiments. The numbers of film layers used for wrapping were 2, 4, 6 or 2+2 (2 layers wrapped in the usual direction followed by 2 layers wrapped in the reverse direction). The moisture contents of the silage were 20, 40 or 50%. No mold was observed after 2 months in silage bales wrapped with 4 or 6 film layers. The mean temperatures at the center of those bales ranged from 25 to 30℃. Silage fermentation was poor, but V score increased as the DM content increased. The DMI values of silage with 20, 40, 50% moisture contents and of hay made from the same herbage as that used for silage were 49, 53, 43 and 51 g/ kgBW^<0.75>/d, respectively. After 11 months of storage, mold was not observed in silage bales wrapped in 4, 6 or 2+2 film layers, and there were no differences in chemical composition or fermentation characteristics between those silage bales. However, an abundance of surface mold was observed in silage bales wrapped in 2 film layers. The temperature of the silage wrapped in film layers that had intentionally ripped rose to 48℃, and mold had grown around the rip after only one week. The results of this study showed that the quality of round bales of low-moisture timothy silage can be preserved by wrapping the bales in at least four layers of film that has no rips.
