THE EFFECT OF APPLYING LACTIC-ACID BACTERIA AT ENSILING ON THE AEROBIC STABILITY OF SILAGES

The effect of applying commercial lactic acid bacteria inoculants at e nsiling on the aerobic stability of silages was studied under laborato ry conditions. The silages used were wheat, hedysarum, corn and variou s sorghum cultivars at various stages of maturity. Three inoculants we re used, two containing Lactobacillus plantarum, Enterococcus faecium and Pediococcus acidilactici (H/M F, Medipharm, USA and Sil-All, Allte ch, UK) and one containing Ent. faecium (Lacticil, M74, Medipharm, Swe den). The inoculants were applied at 0.5 x 10(6) cfu g(-1). Silages wi th no additives served as controls. After treatment, the chopped forag es were ensiled in 1.51 anaerobic jars; there were six jars per treatm ent. After ensiling for 45 d, the silages were tested for aerobic stab ility in a test in which CO2 production was measured along with chemic al and microbiological parameters. The inoculated silages that spoiled upon aerobic exposure faster than the controls were those of wheat an d of the sorghum cultivar FS5 at the milk stage of maturity. This was evident from intensive CO2 production and development of yeasts and mo ulds. Regression analysis indicated that aerobic deterioration of inoc ulated silages was associated with high levels of residual water-solub le carbohydrates and lactic acid and lack of volatile fatty acids. Aer obic spoilage of inoculated silages was attributed mainly to yeast act ivity.