Effects of Different Types of LAB on Dynamic Fermentation Quality and Microbial Community of Native Grass Silage during Anaerobic Fermentation and Aerobic Exposure

Abstract

Silage of native grasses can alleviate seasonal forage supply imbalance in pastures and provide additional sources to meet forage demand. The study aimed to investigate the effects of Lactobacillus plantarum (LP), Lactobacillus buchneri (LB), and Lactobacillus plantarum in combination with Lactobacillus buchneri (PB) on the nutritional quality, fermentation quality, and microbial community of native grass silage at 2, 7, 15, and 60 days after ensiling and at 4 and 8 days after aerobic exposure. The results showed that dry matter content, crude protein content, the number of lactic acid bacteria, and lactic acid and acetic acid content increased and pH and ammonia nitrogen content decreased after lactic acid bacteria (LAB) inoculation compared with the control group (CK). LP had the lowest pH and highest lactic acid content but did not have greater aerobic stability. LB maintained a lower pH level and acetic acid remained at a higher level after aerobic exposure; aerobic bacteria, coliform bacteria, yeast, and molds all decreased in number, which effectively improved aerobic stability. The effect of the compound addition of LAB was in between the two other treatments, having higher crude protein content, lactic acid and acetic acid content, lower pH, and ammonia nitrogen content. At the phylum level, the dominant phylum changed from Proteobacteria to Firmicutes after ensiling, and at the genus level, Lactiplantibacillus and Lentilactobacillus were the dominant genera in both LAB added groups, while Limosilactobacillus was the dominant genus in the CK treatment. In conclusion, the addition of LAB can improve native grass silage quality by changing bacterial community structure. LP is beneficial to improve the fermentation quality in the ensiling stage, LB is beneficial to inhibit silage deterioration in the aerobic exposure stage, and compound LAB addition is more beneficial to be applied in native grass silage.

Effects of kinds of additives on fermentation quality, nutrient content, aerobic stability, and microbial community of the mixed silage of king grass and rice straw

“…At the phylum level, the dominant phyla in the mixed silage of king grass and rice straw were Firmicutes and Proteobacteria, which aligned with the findings in previous studies ( Liu M. et al, 2022 ; Zhang et al, 2023 ). The phylum Firmicutes contains numerous lactic acid bacteria that are actively involved in the process of fermentation, which plays a crucial role in the production of lactic acid during the later stage of ensiling ( Zhao et al, 2017 ).…”

Effects of Different Lactic Acid Bacteria in Single or Mixed Form on the Fermentative Parameters and Nutrient Contents of Early Heading Triticale Silage for Livestock

“…There is evidence that the LAB treatments performed in mixed form produce higher LA and significantly reduce unwanted microbes in comparison with single strain treatments. In addition, a LAB co-culture treatment extends the fermented silage storage time while preserving nutrients [13,18,19,32]. Considering the observations above, whole-crop triticale silage was produced under different moisture conditions in the presence of different LAB strains, using either single or co-culture treatments, for 180 and 360 days.…”

Effects of Vachellia mearnsii Tannin Extract as an Additive on Fermentation Quality, Aerobic Stability, and Microbial Modulation of Maize Silage

“…Other studies have reported that lactic acid bacteria (LAB) inoculants affect the silage microbiology by increasing the abundance of specific bacteria over others [20,[31][32][33]. For example, the increase in abundance of Limosilactobacillus and Lentilactobacillus bacterial genera have been reported for silages treated with LAB inoculants during ensiling [20,[33][34][35]. These changes in silage bacterial composition are associated with the improved quality [33,35,36] and aerobic stability of open silage [20].…”

“…For example, the increase in abundance of Limosilactobacillus and Lentilactobacillus bacterial genera have been reported for silages treated with LAB inoculants during ensiling [20,[33][34][35]. These changes in silage bacterial composition are associated with the improved quality [33,35,36] and aerobic stability of open silage [20]. The manipulation of the silage microorganisms' compositional structure is critical for improving the silage quality and nutrient-use efficiency [35].…”

“…These changes in silage bacterial composition are associated with the improved quality [33,35,36] and aerobic stability of open silage [20]. The manipulation of the silage microorganisms' compositional structure is critical for improving the silage quality and nutrient-use efficiency [35]. Therefore, the objectives of this study were to evaluate the effects of Vachellia mearnsii (formerly known as Acacia mearnsii) condensed tannin as a silage additive on the fermentative quality, aerobic stability, and modulation of microbial composition.…”