SILAGE FERMENTATION AND IN-VITRO DEGRADATION OF MONOSACCHARIDE CONSTITUENTS OF WHEAT HARVESTED AT 2 STAGES OF MATURITY

Wheat plants (Triticum aestivum) were harvested at the bloom and soft- dough stages and ensiled in laboratory silos, and the effect of stage of maturity on the recovery of soluble and cell wall components and on the in vitro digestibility of monosaccharide residues was examined. A total of 8-9% neutral detergent fiber (NDF) monosaccharides residues was solubilized and partly utilized during ensilage. Glucose and galac tose were the most fermentable sugars among the ND soluble monosacchar ides. Fructose was equally fermented in both silages, but the higher r ecovery of reducing sugars in the soft-dough silage as compared with t he bloom silage (44.1 vs 26.8) indicates the possible participation of starch in the fermentation process of the former. Generally, the sila ges were less digestible than the source materials, but the difference was larger in the bloom treatment. Thus, a gap of 8.1 percentage unit s in total NDF monosaccharide digestibility (D) between the source mat erials was reduced to 5.5 units between the silages. The decline in th e D values of the monosaccharide residues of the whole plant following ensilage was 11.5 and 6.0 percentage units for the bloom and soft-dou gh stages, respectively. The D of total monosaccharide residues of who le plant material was equal within,the source materials but was 5.3 pe rcentage units higher in the soft-dough silage than in the bloom one. Digestibility measurement at the monosaccharide level of source materi als and silages offers a sharp tool for determining the optimal stage for harvesting wheat for silage.