High-throughput sequencing based on a novel Clostridia-specific primer set proved a potentially useful tool to study the clostridial community dynamics, and could aid to elucidate the mechanism by which the clostridial fermentation develops during the ensiling of alfalfa.

Chemical‐compositional characteristics of crops are crucial factors affecting the fermentation profile and aerobic stability of silages. To evaluate the effects of starch content and buffering capacity, fresh smooth bromegrass was ensiled alone (control), with 9% maize meal (MM), or with a mixture of 9% maize meal and 1.5% limestone (MX) on a fresh matter basis in sealed plastic bags. After 1, 3, 14 and 56 days of ensiling, triplicate bags of each treatment were opened for chemical and microorganism analyses, and then the samples ensiled for 56 days were placed in polyethylene containers to evaluate their aerobic stability. During the early days of ensiling, the mixtures of maize meal and limestone favoured lactic acid bacteria growth, lactic acid production and decrease in pH values. After 56 days of ensiling, the MX‐treated silages had significantly higher (p < .05) lactic acid, ammonia‐N and buffering capacity compared with the silages treated with other additives. The aerobic stability of MM‐treated silages was significantly lower (p < .05) than that of the control silages, but the MX‐treated silages showed higher (p < .05) aerobic stability than the other groups. The changes of organic acids and pH in the MX‐treated silages were also delayed, which inhibited the growth of aerobic bacteria and yeasts. These results indicate that maize meal improved the fermentation profile of smooth bromegrass silage but had a negative effect on its aerobic stability; however, limestone played important roles in both accelerating fermentation and the improvement of aerobic stability.

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This study aimed to investigate the effects of low-temperature-tolerant lactic acid bacteria on the fermentation quality and bacterial community of oat silage. Silage treatments were designed as control (with no additives), with FO3, FO5, FO8, and L214 inoculants. After 60 days of ensiling, the fermentation characteristics and bacterial community were analyzed. The results showed that the low-temperature-tolerant lactic acid bacteria were able to reduce the pH and NH3-N and increase crude protein and lactic acid contents. It is worth noting that the addition of FO3 also significantly inhibited butyric acid production. High-throughput sequencing technique showed that at the genus level, Lactiplantibacillus were the dominant bacteria in all oat silages, while at the species level, the bacterial abundance in the treated silages differed significantly from the control. The highest abundance of Lactiplantibacillus sp. was found in the control and L214 groups, while the abundance of Lactiplantibacillus curvatus was most abundant in the silage treated with low-temperature-tolerant lactic acid bacteria. The results indicated the potential effectiveness of low-temperature-tolerant lactic acid bacteria in improving fermentation quality and reducing protein losses.

Bacterial inoculants are considered as a good choice for successful ensiling, playing a key role in improving the silage quality. However, the potential of different bacteria, especially the propionic acid bacteria, in forage oat ensiling is yet to be explored. Therefore, the purpose of this study was to investigate the regulation effects of different bacterial additives on the fermentation quality of forage oat silage. Four additives (Lactiplantibacillus plantarum F1, LP; Lacticaseibacillus 0rhamnosus XJJ01, LR; Lacticaseibacillus paracasei XJJ02, LC; and Propionibacterium acidipropionici 1.1161, PP; without additives, CK) were inoculated in forage oat silage, and the fermentation quality and organic compounds were determined after 60 days of ensiling. Notably, LR showed higher dry matter preservation compared to other additives and CK. In addition, LP and LR showed strong lactic acid synthesis capacity, resulting in lower pH compared to other additives and CK. The treatments of PP and LC increased the bacterial diversity in silage, while the bacterial community in the LR group was different from that in other groups. In addition, the PP- and LC-treated oat silage showed significantly lower total in vitro gas production and a lower methane content. These results suggest that LP is more favorable for producing high-quality oat silage than LR, LC, or PP. Both the PP- and LC- treated oat silage may reduce rumen greenhouse gas emissions.