When grass with an adequate content of fermentable substrate and epiphytic lactic acid bacteria is ensiled properly, the fermentation which follows is normally considered satisfactory. This fermentation can be altered by various categories of additive such as acids, sugars and inoculants, each of which can influence the fermentation differently. The experiment reported compared the fermentation products, aerobic stability and animal performance for silages made using formic acid or a Lactobacillus plantarum inoculant with well preserved silage made without additive treatment.

A 42 day regrowth of Lolium multiflorum (cv. Lemtal) was harvested without wilting using two precision - chop harvesters. Alternate loads of grass were ensiled with (a) no additive, (b) formic acid (850g/kg) at 3.0 1/t or (c)inoculant (Ecosyl - ICI plc) at 3 1/t (separate harvester). The inoculant was constituted immediately before use and was applied in accordance with the manufacturers instructions. Harvesting was completed and the silos sealed within 26 hours of mowing. The silos were opened after 113 days.