Chemical changes and losses during the ensilage of wilted grass treated with formic acid

Abstract

Formic acid (85%) was added to wilted perennial ryegrass (36% dry matter) at the rate of 0.39%. Changes during ensilage of this material were compared with changes occurring during ensilage of untreated wilted ryegrass and freshly harvested herbage. All silages were well preserved, of low volatile N content and contained only traces of butyric acid. Formic acid restricted fermentation in the wilted grass resulting in silage of high water‐soluble carbohydrate content (15.3%) compared with untreated wilted (4.7%) and fresh (1.2%) silages. Results of microbiological studies indicated that yeasts were more active in the formic acid‐treated herbages. Surface waste production and fermentation plus oxidation losses were higher in the acid‐treated wilted silages (21%) than in the untreated wilted materials (14%).