The type of silage additive will influence the characteristics of fermentation, dry matter (DM) losses, hygienic quality and aerobic stability of silage. The appropriate use of an additive also depends on the crop to which it is applied. Homofermentative lactic acid bacteria (LAB) strains are selected for rapid growth under under variable temperatures, herbages and dry matter concentrations. The homofermentative LAB are highly competitive and produce largely lactic acid and reduce pH and ammonia-N content compared to untreated silage (Muck 2012). Heterofermentative LAB such as Lactobacillus buchneri reduce the growth of yeast and mould and increase aerobic stability. These effects are retained when heterofermentative LAB are added in combination with homofermentative LAB (Kleinschmit et al. 2005). An alternative to the combination of homo- and heterofermentative inoculants is to use homofermentative LAB in combination with a chemical component such as sodium benzoate (NaBe). In an experiment by Jaakkola et al. (2010) a combination of Lactobacillus plantarum and sodium benzoate were more efficient than Lactobacillus plantarum and Lactobacillus buchneri to prevent heating of silage. The objective of the study was to investigate efficacy of different inoculant types on fermentation characteristics and aerobic stability of Lucerne (L), ryegrass (R), red clover-ryegrass (RCR) and ryegrass-timothy (RT) silages
