In a previous study carried out at this Institute the application of a bacterial inoculant to unwilted grass at ensiling produced significant increases in silage DM intake and milk production across 3 harvests, while the use of the inoculant with wilted grass silages indicated no benefits in those two parameters (Yan, Patterson and Gordon, 1995). The reason for the lack of improvement when the inoculant was used with wilted grass silages was unclear, but could partially reflect greater potential rates of aerobic deterioration with wilted inoculated than wilted untreated silages during the feeding-out period. The present study was designed to further investigate the effects of inoculation of both unwilted and wilted grass silages.

A set of four silages, comprising unwilted and wilted material, both with and without application of one of four bacterial inoculants at ensiling, was prepared from perennial ryegrass swards on each of 8 harvesting occasions during 1994.