The effects of silage inoculants on the fermentation and aerobic stability of legume-grass silage

The effects of silage additives homofermentative lactic acid bacteria (LAB) strains Entrococcus faecium, Lactococcus lactis, Lactobacillus plantarum; homo- and heterofermentative LAB strains Lactobacillus plantarum, Entrococcus faecium and L. buchneri; homofermentative LAB strains plus sodium benzoate; homofermentative LAB strains plus xylanase and homofermentative LAB strains plus xylanase and plus sodium nitrate on the fermentation and aerobic stability of legume-grass silages were studied under laboratory conditions. The second cut (265 g kg(-1) dry matter) of a mixture of red clover and perennial ryegrass (1:1) stand was harvested with standard field equipment. After inoculants were added, the chopped forages were ensiled in a 3.0 litre anaerobic glass jars and compared with control silage prepared without an inoculant. The silages were opened after 90 days of ensiling and their chemical composition was measured. Silages were also assessed for aerobic stability. Overall, microbial inoculants generally had a positive effect on grass-legume silage characteristics in terms of lower pH, ammonia-N concentrations, reduced DM losses and populations of yeasts and mould compared with control silages. The final pH and DM loss was lowest for silages inoculated with homofermentative LAB in combination with xylanase and for silages inoculated with homofermentative LAB in combination with xylanase and sodium nitrate. Homofermentative LAB in combination with L. buchneri or sodium benzoate shifted fermentation toward acetate and had a great effect on aerobic stability of slightly wilted red clover-ryegrass silages.