Effects of Different Inoculant Types on the Fermentation Characteristics of Silages from Various Forage Crops

Silage additives formulated with lactic acid bacteria (LAB) are commonly applied to enhance fermentation efficiency and aerobic stability. However, comparative evaluations across different forage species are still scarce. This in vitro experiment assessed the influence of eleven commercial silage inoculants containing various combinations of homo- and heterofermentative LAB on fermentation dynamics, nutrient conservation, and aerobic stability of medium-wilted alfalfa (Medicago sativa L.), perennial ryegrass (Lolium perenne L.), and red clover/perennial ryegrass silages. Experimental silages were prepared in 3 L laboratory silos and stored for 90 days. All inoculated treatments exhibited significantly lower pH values at both 3 and 90 days of ensiling compared with the untreated control (p < 0.05). LAB application increased the concentration of total fermentation acids and lactic acid in all forage types, although responses varied depending on inoculant composition. Inoculants containing Lentilactobacilllus buchneri produced the greatest acetic acid concentrations and resulted in a marked enhancement of aerobic stability. Compared with the control, silage inoculation significantly decreased dry matter losses by 35–64% and ammonia-N proportion by 20–37%, leading to an additional dry matter recovery of 1.29–2.87%. Control silages showed the lowest aerobic stability (97.2 h), while inoculated silages ranged from 126.0 to 200.4 h, with the extent of improvement differing among forage species and LAB formulations. In conclusion, commercial silage inoculants incorporating diverse LAB strains effectively improve fermentation quality, limit nutrient degradation, and enhance aerobic stability of legume and grass silages under controlled experimental conditions.