Degradation of Cell Wall Constituents of Guineagrass (Panicum maximum Jacq.) during Ensiling

Abstract

Guineagrass (Panicum maximum Jacq.) was ensiled into a laboratory bag silo for the investigation of the degradation of cell wall constituents during silage fermentation. The resultant silage was "acetic acid silage" with high pH and low lactic acid content. The most of ADF, lignin and cellulose of guineagrass were recovered from the silage, but parts of NDF and hemicellulose had disappeared. This indicates that cell wall decomposition occurred mostly in the hemicellulose fraction. The recovery of hemicellulose-derived monosaccharides from the silage was low for glucose and galactose, but was high for xylose and uronic acids. About 20% of dry matter and 30% of digestible dry matter (in vitro) had disappeared. It is suggested that hemicellulose fermentation plays an important role in ensiling of tropical grasses.