The effects of wilting, molasses and inoculants on the fermentation quality and nutritive value of lucerne silage

Abstract

The objective was to determine the effects of wilting, molasses and inoculants on the biochemistry and in vitro and in situ digestion of lucerne silage. Lucerne containing 200 g/kg of dry matter (DM) was ensiled as fresh or wilted (370 g/kg DM). Molasses, at application rates of 0, 50 and 100 g molasses/kg DM, was added to the chopped lucerne. Within each molasses treatment, the lucerne was applied with distilled water or with theinoculants, Ecosyl or Lalsil. Wilting lucerne increased the silage DM and  water soluble carbohydrates and decreased neutral detergent fibre, acid detergent fibre, ammonia and the acetate content of the silage. Adding 50 and 100 g molasses/kg to wilted lucerne and 100 g molasses/kg to fresh lucerne lowered the silage pH. Adding molasses to wilted lucerne increased the acetate content of the silage. In wilted but not in fresh lucerne both inoculants decreased the concentration of unavailable N in the silage. In wilted lucerne, Lalsil, but not Ecosyl, reduced the silage acetate level and infresh lucerne both inoculants reduced the acetate level. Lalsil was more  effective in wilted silages in improving the fermentation quality than Ecosyl. Both inoculants enhanced the 24-h rumen degradation of silage DM, with Lalsil being effective in wilted lucerne and Ecosyl in fresh lucerne. Molasses, at 100 g/kg, improved the in vitro silage organic matter digestion at 6, 8, 36 and 48 h post-incubation. It was concluded that inoculating lucerne crops with Lalsil improved the fermentation quality as well as nutritive value and lowered proteolysis. These effects were more pronounced in silage with a high DM content.

Keywords: Alfalfa silage, chemical composition, Ecosyl, Lalsil, additive, wilting, gas production