The efficacy of inoculant silage additives has often been questioned under difficult ensiling conditions. This study was conducted under testing conditions to test the efficacy of an inoculant additive (SA55) on silage fermentation and animal performance.

A perennial ryegrass (Lolium perenne) based sward was mown and conditioned on 29 October 1996 and was picked up on 30 and 31 October. Two similar precision-chop forage harvesters were used, one picked up grass without applying additive (Control), whilst the second applied the inoculant additive (SA55). SA55 (Microferm Ltd) was applied at a target rate of 2 1/t to give 5 x 105 organisms (Lactobacillus plantarum, Paediococcus acidilactici, Lactococcus lactis lactis and clostridial bacteriophages) per gramme of grass. The harvesters picked up adjacent swaths and dedicated trailers serviced each harvester. Frequent checks were made on the application rate of the additive. Two similar, roofed bunker silos were loaded with grass, using loaders dedicated to each silo. Loads of grass were tipped in their respective silos to avoid Cross contamination during the filling operation. Care was taken to ensure equal consolidation of both clamps. After consolidation, clamps were sealed with polythene sheeting and weighted down with tyres. Each load of grass was weighed and sampled.