Fermentative Characteristics in Italian Ryegrass Silage by Multiple Probiotic Inoculants Based on Lactiplantibacillus plantarum

Silage inoculants, which include beneficial microorganisms like lactic acid bacteria (LAB), play a vital role in modern silage production by enhancing fermentation quality. This study evaluated the effectiveness of various commercial inoculants on the fermentation dynamics of Italian ryegrass silage over 45 days. The treatments included a control group and five inoculant formulations: T1 (Lactiplantibacillus plantarum), T2 (Lactiplantibacillus plantarum and Pediococcus pentosaceus), T3 (Lactiplantibacillus plantarum and Pediococcus pentosaceus and Lactiplantibacillus buchneri), T4 (Lactiplantibacillus plantarum and Lactiplantibacillus acidophilus and Lactiplantibacillus bulgaricus), and T5 (Lactiplantibacillus plantarum and Pediococcus pentosaceus and Enterococcus faecium). After 45 days, all treatment groups exhibited significantly higher crude protein (CP) content compared to the control group (80.64 g/kg dry matter (DM), p<0.05). Treatments T2 and T5, which incorporated combinations of Lactiplantibacillus plantarum, Pediococcus pentosaceus and Enterococcus faecium, showed higher CP contents at 105.53 and 107.05 g/kg DM, respectively. The inoculated silages also demonstrated a rapid pH reduction within the early days, with Lactiplantibacillus plantarum in T1 reducing the pH to 4.0 within four days. Additionally, inoculated treatments had significantly higher lactic acid levels than the control (67.96 g/kg DM, p<0.05), and T3 (Lactiplantibacillus buchneri) produced higher acetic acid levels (16.07 g/kg DM, p<0.05) than other inoculants. The control group also had a notably higher ammonia nitrogen content. In conclusion, while single-strain inoculants like Lactiplantibacillus plantarum are effective for rapid acidification, the use of combined bacterial strains can further enhance silage quality by improving lactic acid fermentation and nutrient preservation, particularly in treatments like Lactiplantibacillus plantarum and Pediococcus pentosaceus and Lactiplantibacillus buchneri and Enterococcus faecium.