The objective of this study was to investigate how storage temperatures influence the bacterial community of oat silage during the ensiling process via PacBio single molecule, real-time sequencing technology (SMRT). Forage oat was ensiled at four different temperatures (5 °C, 10 °C, 15 °C, and 25 °C) and ensiling days (7, 14, 30, and 60 days). With the rise in storage temperature, the lactic acid content showed an increased trend. Acetic acid production was observed highest in silage fermented at 5 °C compared with other treatments, and Enterococcus mundtii was also the dominant bacterial species. Lactiplantibacillus pentosus and Loigolactobacillus rennini were exclusively detected in silages at 10 °C, 15 °C, and 25 °C, and dominated the fermentation after 60 days of ensiling at 10 °C and 25 °C, respectively. In addition, L. pentosus, L. rennini, and E. mundtii may be related to changes in the fermentation products due to the differences in ensiling temperature. In conclusion, results of this study improve our understanding of the complicated microbial composition underlying silage fermentation at low temperatures, which might contribute to target-based regulation methods for enhancing silage quality and developing new inoculants.

Oat natural silage is rich in Enterobacteriaceae , increasing gas production and fermentation loss. Lactic acid bacteria interact synergistically to form a dominant community during ensiling. Pediococci grow vigorously in the early stage of fermentation and create an anaerobic environment. Lactobacilli inhibit the harmful microorganisms and result in cleaner fermentation of oat silage.

Packing density has a significant influence on the outcome of ensiling forage. In this study, we aim to investigate the effect of packing density on the ensiling properties, microbiome, and in vitro digestibility of barley silages. Barley was ensiled in polyethylene drum silos (30 L) with respective densities of 600, 650, 700, and 750 kg/m³ fresh matter (FM), and stored for 60 days. The bacterial communities, fermentation quality, and in vitro digestibility were analyzed. Fresh barley had a low count of lactic acid bacteria (LAB, 10⁴ cfu/g of FM), and Lactobacillus was nearly undetectable (<1%). Increasing the packing density decreased the pH and the content of ammonia nitrogen (NH₃-N), ethanol, neutral detergent fiber (NDF), and acid detergent fiber (ADF) of barley silage (p < 0.05), and increased in vitro digestibility of dry matter, NDF, ADF, and DM recovery (p < 0.05). A higher packing density decreased the abundances of Enterobacter (from 47.4% to 35.4%) and Clostridium (from 13.5% to 3.8%), and increased the abundance of Lactobacillus (from 1.8% to 17.0%). Thus, packing density positively correlated with Lactobacillus (p < 0.05) but negatively correlated with Enterobacter (p < 0.05). The pH and the content of ethanol were positively correlated with Enterobacter (p < 0.05) but negatively correlated with Lactobacillus (p < 0.05). In conclusion, the density of 750 kg/m³ FM resulted in the highest silage quality of the densities tested.

The aim of this study was to evaluate the effects of cellulase (CE) and lactic acid bacteria (LAB) on Caragana korshinskii silage by analyzing the fermentation parameters, chemical composition, and bacterial community. The Caragana korshinskii was harvested at the fruiting period and treated with cellulase and LAB alone as a control treatment with no additive (CK). The ensiling performance and bacterial community were determined after 3, 7, 15, 30, and 60 days of fermentation process. Compared with the CK group, the pH, dry matter loss, and ammonia nitrogen content were significantly (p < 0.05) decreased in the LAB and CE treatments. Compared with the CK and LAB group, the contents of acid detergent fiber, neutral detergent fiber, and acid detergent lignin in the CE group decreased significantly (p < 0.05), and the water-soluble carbohydrates, acetic acid, and lactic acid concentrations increased significantly (p < 0.05). At the genus level of microorganisms, the addition of cellulase and LAB significantly reduced the microbial diversity. Compared with the CK group (78.05%), the relative abundance of Lactiplantibacillus in the CE group (90.19%) and LAB group (88.40%) significantly (p < 0.05) increased. The relative abundance of Pediococcus in the CE group (3.66%) and LAB group (2.14%) was significantly (p < 0.05) lower than that in the CK group (14.73%). Predicted functional profiling of 16S rRNA genes revealed that the addition of cellulase and LAB increased the pyruvate metabolic pathway during Caragana korshinskii silage, thereby increasing the accumulation of lactic acid concentration. The addition of cellulase expressed a better advantage in the biosynthetic capacity of lysine. In summary, the addition of cellulase and LAB could adjust the bacterial community to improve the silage quality of Caragana korshinskii, and the addition of cellulase exhibited better results than the LAB additives.

This study examined the effects of chopping or chopping + blender maceration of red clover or lucerne on pre-fermented juice (PFJ) and determined the effects of PFJs on the quality of red clover silage or lucerne silage. The PFJs from chopping red clover (PFJ-RC) or lucerne (PFJ-LC) had a higher lactic acid bacteria (LAB) count than that from chopping + blender maceration (p < 0.05) and were used as additives. Compared with the Control of both silages, adding PFJ increased LAB, lactic acid (LA), and in vitro digestibility of dry matter (IVDMD) (p < 0.05), while pH, acetic acid (AA), and ammonia nitrogen/total nitrogen (NH₃-N/TN) were decreased (p < 0.05). For red clover silages, the PFJ-RC treatment contained the greatest LAB and LA and the lowest pH and NH₃-N/TN among treatments (p < 0.05); similar results were observed in PFJ-LC treatment for lucerne silages (p < 0.05). The IVDMD of both silages correlated negatively with pH, AA, and NH₃-N/TN and positively with LA (p < 0.05). Overall, chopping alone was a better method for preparing PFJ. Adding PFJ at ensiling increased LA and decreased the pH, AA, and NH₃-N/TN of both silages. Ensiling lucerne or red clover with PFJ from the ensiling material had a more positive effect on the fermentation parameters mentioned above. Satisfactory fermentation parameters detected in the present study contributed to improving the IVDMD of both silages.