The selection of lactic acid bacteria for use as silage additives is normally based upon their ability to dominate the silage fermentation and not upon benefits in animal performance. The object of this study was to investigate whether two lactic acid bacteria selected for fermentation characteristics would support the same animal performance as an established silage inoculant.

On 5 June 1989, first cut, predominantly perennial ryegrass (Lolium perenne) was ensiled direct with no wilting in plastolene silos of 2 tonne capacity. The herbage was harvested with a precision chop forage harvester and the following additive treatments were applied: None, control (C); Formic acid (Add-F, BP Nutrition, 850g/kg; 3 litres/tonne), (F); inoculant E. (Ecosyl, ICI Pic, 106Lactobacillus plantarum /g): inoculant A, (Pediococcus sp, 10 /g); inoculant B (L. plantarum 106 /g). The silages were fed to 6 wether sheep (Suffolk x Halfbred), initial live-weight, 40.1 kg (s.d. 2.22kg). Because the silages were unstable aerobically and restricted quantities of each silage were available, all sheep were fed the silages in the same (random) order.