Effects of fibrolytic enzymes and lactic acid bacteria on fermentation quality and in vitro digestibility of Napier grass silage

Abstract

An experiment was conducted to evaluate the effect of xylanase and cellulase derived from dried tomato pomace treated with Aspergillus niger and fermented juice of epiphytic of lactic acid bacteria (FJLB) on fermentative quality and in vitro digestibility of Napier grass silages. Thus, we treated Napier grass silage with or without fibrolytic enzymes (ENZ) in combination with or without FJLB. The pH values of silages treated with FJLB, but not ENZ, were found to be lower than the other silages during the ensiling process. The content of water soluble carbohydrates (WSC) of all silages was likely to decrease during fermentation in all silages. However, after 30 days of ensiling, the addition of ENZ resulted in higher WSC content when compared to the other treatments. At 30 day of ensiling, the crude protein of silage was higher in silage treated with FJLB. The gas production related to the soluble fraction was higher in silage treated with ENZ but total gas production was similar between treatments. The latter is in line the observation that the degradability of organic matter also was not different between treatments. It is concluded that neither the fermentation quality nor the in vitro digestibility of organic matter is improved when Napier grass is ensiled with both FJLB and fibrolytic enzymes compared with FJLB alone.Highlights Ensiling Napier grass, which contains high water soluble carbohydrates, without additives results in an acceptable fermentation quality. A combination of fermented juice of epiphytic lactic acid bacteria (FJLB) and fibrolytic enzymes has no effect on quality of Napier grass silage.

Keywords

• gas production
• inoculant
• nutritive value
• volatile fatty acid