The role of additives when ensiling red clover-grass mixture for biogas production

摘要

A second cut from a mixed sward of red clover, timothy and meadow fescue was prewilted and harvested with a precision chopper. The grass had a dry matter (DM) concentration of 357 g kg~(-1), while water soluble carbohydrates were 66, crude protein 122, and D-value 596 g kg~(-1) DM. The grass was ensiled without an additive (control), with Lactobacillus buchneri, with Lactobacillus plantarum or with AIVr2Plus. Addition of AIVr2Plus restricted silage fermentation as judged by high residual sugar and low lactic acid concentrations. Plantarum silages had a homolactic fermentation profile with low pH, high lactic and low acetic acid concentrations. Buchneri silages had a heterolactic fermentation profile with high acetic and propionic, and low lactic acid concentrations. There were no statistically significant differences between treatments in biochemical methane potential of the silages. DM losses during ensiling were 27, 35, 10, and 14 g kg~(-1) DM for Control, Buchneri, Plantarum and AIVr2Plus silages, respectively. The losses after silo opening during 259 h aerobic phase were 42, 3, 143 and 9 g kg~(-1) DM, respectively. The high DM loss during the aerobic phase in the Plantarum silages was related to high counts of enterobacteria and fungi.