Recent studies have shown that the use of an effective bacterial inoculant as a silage additive results in improvements in animal performance of dairy and beef cattle. Treatment with an inoculant based on a single strain of L. plantarum has increased silage digestibility and altered the composition of rumen fluid in beef cattle (Keady and Steen, 1994 and 1995). Inoculant products vary in composition, containing different bacteria species and numbers, possibly with the addition of enzymes, clostridiaphages and rumen enhancers. The present study was designed to evaluate an inoculant containing mixed strains of bacteria, enzymes, bacteriophages and a rumen enhancer through lactating dairy cattle and to study its effects on diet digestibility and rumen fermentation patterns.

Herbage was harvested from the primary regrowth of a predominantly perennial ryegrass sward, which had received 99 kg nitrogen (N) per ha after the previous harvest, after a fifty-one day regrowth interval. Herbage was mown down using a mower conditioner and picked up immediately, unwilled, using a precision chop harvester.