This study was conducted to examine the effects of Lactobacillus plantarum (LP) and sucrose (S) on clostridial community dynamics and correlation between clostridia and other bacteria in alfalfa silage during ensiling. Fresh alfalfa was directly ensiled without (CK) or with additives (LP, S, LP + S) for 7, 14, 28 and 56 days. Clostridial and bacterial communities were evaluated by next-generation sequencing. Severe clostridial fermentation occurred in CK, as evidenced by the high contents of butyric acid, ammonia nitrogen, and clostridia counts, whereas all additives, particularly LP + S, decreased silage pH and restrained clostridial fermentation. Clostridium perfringens and Clostridium butyricum might act as the main initiators of clostridial fermentation, with Clostridium tyrobutyricum functioning as the promoters of fermentation until the end of ensiling. Clostridium tyrobutyricum (33.5 to 98.0%) dominated the clostridial community in CK from 14 to 56 days, whereas it was below 17.7% in LP + S. Clostridium was negatively correlated with the genus Lactobacillus, but positively correlated with the genera Enterococcus, Lactococcus and Leuconostoc. Insufficient acidification promoted the vigorous growth of C. tyrobutyricum of silage in later stages, which was mainly responsible for the clostridial fermentation of alfalfa silage.

This study investigated the association of enzyme-producing microbes and their enzymes with starch and hemicellulose degradation during fermentation of total mixed ration (TMR) silage. The TMRs were prepared with soybean curd residue, alfalfa hay (ATMR) or Leymus chinensis hay (LTMR), corn meal, soybean meal, vitamin-mineral supplements, and salt at a ratio of 25:40:30:4:0.5:0.5 on a dry matter basis. Laboratory-scale bag silos were randomly opened after 1, 3, 7, 14, 28, and 56 days of ensiling and subjected to analyses of fermentation quality, carbohydrates loss, microbial amylase and hemicellulase activities, succession of dominant amylolytic or hemicellulolytic microbes, and their microbial and enzymatic properties. Both ATMR and LTMR silages were well preserved, with low pH and high lactic acid concentrations. In addition to the substantial loss of water soluble carbohydrates, loss of starch and hemicellulose was also observed in both TMR silages with prolonged ensiling. The microbial amylase activity remained detectable throughout the ensiling in both TMR silages, whereas the microbial hemicellulase activity progressively decreased until it was inactive at day 14 post-ensiling in both TMR silages. During the early stage of fermentation, the main amylase-producing microbes were Bacillus amyloliquefaciens (B. amyloliquefaciens), B. cereus, B. licheniformis, and B. subtilis in ATMR silage and B. flexus, B. licheniformis, and Paenibacillus xylanexedens (P. xylanexedens) in LTMR silage, whereas Enterococcus faecium was closely associated with starch hydrolysis at the later stage of fermentation in both TMR silages. B. amyloliquefaciens, B. licheniformis, and B. subtilis and B. licheniformis, B. pumilus, and P. xylanexedens were the main source of microbial hemicellulase during the early stage of fermentation in ATMR and LTMR silages, respectively. The microbial amylase contributes to starch hydrolysis during the ensiling process in both TMR silages, whereas the microbial hemicellulase participates in the hemicellulose degradation only at the early stage of ensiling.

The objective of this study was to evaluate the effect of Pediococcus pentosaceus inoculation on the fermentation quality and the dynamics of microbial communities during ensiling and aerobic exposure in total mixed ration (TMR) silage. The TMR were prepared using alfalfa (Medicago sativa L.), maize meal, soybean curd residue, soybean meal, calcium carbonate, vitamin‐mineral supplement and salt (60.0:21.4:15.0:2.0:1.0:0.5:0.1, dry matter basis) with or without P. pentosaceus inoculation (10⁵ cfu/g fresh matter) followed by 14 or 28 days of ensiling and exposed to air. Microbial communities were detected by high‐throughput sequencing. After ensiling, P. pentosaceus inoculation benefited silage fermentation as indicated by increased lactic acid content and decreased pH, whereas had no effect on aerobic stability. Taxonomic bacterial community was dominated by Lactobacillales after ensiling, with a notable increase in spoilage microorganisms as a result of aerobic exposure. Aerobically exposed TMR was characterized by an increase of operational taxonomic units belonging to the Hypocreales and with yeast genus Cryptococcus, whereas Monascus was the major mold genus in the aerobically exposed silages. Candida was detected with higher relative abundance only in 28 days aerobically exposed sample inoculated with P. pentosaceus. P. pentosaceus inoculation has good effects on improving the fermentation quality and shows a potential to inhibit the proliferation of Monascus at 28 days of ensiling.

The objective of this study was to assess the use of peach pomace in total mixed ration (TMR) silages and clarify the differences in aerobic stability between TMR and TMR silages caused by lactic acid bacteria (LAB). The TMR were prepared using peach pomace, alfalfa hay or Leymus chinensis hay, maize meal, soybean meal, cotton meal, limestone, a vitamin-mineral supplement, and salt in a ratio of 6.0:34.0:44.4:7.0:5.0:2.5:1.0:0.1 on a dry matter (DM) basis. Fermentation quality, microbial composition, and the predominant LAB were examined during ensiling and aerobic deterioration. The results indicated that the TMR silages with peach pomace were well fermented, with low pH and high lactic acid concentrations. The aerobic stability of TMR silages were significantly higher than that of TMR. Compared with TMR silages with alfalfa hay, TMR silage with Leymus chinensis hay was much more prone to deterioration. Although the dominant LAB were not identical in TMR, the same dominant species, Lactobacillus buchneri and Pediococcus acidilactici, were found in both types of TMR silages after 56 d of ensiling, and they may play an important role in the aerobic stability of TMR silages.