The aim of this study was to explore the effects of different lactic acid bacteria additives (Lactiplantibacillus plantarum or Lentilactobacillus buchneri) on the fermentation quality, chemical composition, in vitro digestibility, bacterial community structure, and predictive function of S. perfoliatum silage feed. Fresh S. perfoliatum was wilted overnight, then its moisture content was adjusted between 65 and 70%. The experiment was performed in three groups as follows: (1) the control group (CK group), which lacked a Lactobacillus preparation; (2) the Lactiplantibacillus plantarum (L. plantarum) group (LP group), which was inoculated with L. plantarum at 5 × 106 cfu/g FW; and (3) the Lentilactobacillus buchneri (L. buchneri) group (LB group), which was inoculated with L. buchneri at 5 × 106 cfu/g FW. The results showed that L. plantarum significantly reduced pH and increased lactic acid (LA) content in S. perfoliatum silage compared with the control. L. buchneri, on the other hand, excelled in reducing ammonia nitrogen (NH3-N) content and significantly increased acetic acid (AA) content. At 60 days of fermentation, the CP content was significantly higher (p < 0.05) in the LP and LB groups than in the CK group (19.29 vs. 15.53 and 15.87). At 60 days of fermentation, the ivCPD was significantly higher (p < 0.05) in the LB group than in the CK and LP groups (57.80 vs. 54.77 and 55.77). The 60-day silage process completely altered the bacterial community of S. perfoliatum silage. In the fresh samples, the dominant genera were Weissella_A and Pantoea_A. Weissella_A and Pantoea_A were gradually replaced by Lentilactobacillus and Lactiplantibacillus after S. perfoliatum ensiling. After 45 days of fermentation, L. buchneri became the dominant strain in CK, LP and LB groups. Inoculation with L. plantarum altered the succession of the bacterial community from 7 to 15 days of fermentation of S. perfoliatum. In contrast, inoculation with L. buchneri affected the succession of the bacterial community from 30 to 60 days of S. perfoliatum fermentation. In S. perfoliatum silage aged 7 to 60 days, the amino acid metabolic pathway in the LB group remained upregulated. The experimental results revealed that inoculation with L. buchneri had a stronger effect on S. perfoliatum silage than inoculation with L. plantarum. Thus, L. buchneri should be selected as an additive for S. perfoliatum silage fermentation in practical production.
Keywords: Fodder storage; Silphium perfoliatum L.; bacterial community; fermentation quality; lactic acid bacteria additives; silage.