Fermentation Characteristics, Nutrient Content, and Microbial Population of <i>Silphium perfoliatum</i> L. Silage Produced with Different Lactic Acid Bacteria Additives

The aim of this study was to explore the effects of different lactic acid bacteria additives (<i>Lactiplantibacillus plantarum</i> or <i>Lentilactobacillus buchneri</i>) on the fermentation quality, chemical composition, in vitro digestibility, bacterial community structure, and predictive function of <i>S. perfoliatum</i> silage feed. Fresh <i>S. perfoliatum</i> 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 <i>Lactobacillus</i> preparation; (2) the <i>Lactiplantibacillus plantarum</i> (<i>L. plantarum</i>) group (LP group), which was inoculated with <i>L. plantarum</i> at 5 × 10⁶ cfu/g FW; and (3) the <i>Lentilactobacillus buchneri</i> (<i>L. buchneri</i>) group (LB group), which was inoculated with <i>L. buchneri</i> at 5 × 10⁶ cfu/g FW. The results showed that <i>L. plantarum</i> significantly reduced pH and increased lactic acid (LA) content in <i>S. perfoliatum</i> silage compared with the control. <i>L. buchneri</i>, 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 (<i>p</i> < 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 <i>iv</i>CPD was significantly higher (<i>p</i> < 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 <i>S. perfoliatum</i> silage. In the fresh samples, the dominant genera were Weissella_A and Pantoea_A. Weissella_A and Pantoea_A were gradually replaced by <i>Lentilactobacillus</i> and <i>Lactiplantibacillus</i> after <i>S. perfoliatum</i> ensiling. After 45 days of fermentation, <i>L. buchneri</i> became the dominant strain in CK, LP and LB groups. Inoculation with <i>L. plantarum</i> altered the succession of the bacterial community from 7 to 15 days of fermentation of <i>S. perfoliatum</i>. In contrast, inoculation with <i>L. buchneri</i> affected the succession of the bacterial community from 30 to 60 days of <i>S. perfoliatum</i> fermentation. In <i>S. perfoliatum</i> silage aged 7 to 60 days, the amino acid metabolic pathway in the LB group remained upregulated. The experimental results revealed that inoculation with <i>L. buchneri</i> had a stronger effect on <i>S. perfoliatum</i> silage than inoculation with <i>L. plantarum</i>. Thus, <i>L. buchneri</i> should be selected as an additive for <i>S. perfoliatum</i> silage fermentation in practical production.