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.

L. indica L. cv. Mengzao, a medicinal plant of the Ixeris genus, is rich in flavonoids. In order to thoroughly analyze the the distribution and dynamic change of major flavonoids in its various parts from different growth periods, the flavonoids extracted from L. indica L. cv. Mengzao were identified and quantitatively analyzed by ultra-high-performance liquid chromatography mass spectrometer (LC-MS/MS). Results indicated that 15 flavonoids were identified from L. indica L. cv. Mengzao, and rutin, luteolin, luteolin-7-O-glucoside, kaempferol, quercetin, and apigenin are the major flavonoids in L. indica L. cv. Mengzao. In general, the total flavonoids’ content in different parts of L. indica L. cv. Mengzao followed the order flowers > leaves > stems > roots. Flowers and leaves are the main harvesting parts of L. indica L. cv. Mengzao, and the flowering period is the most suitable harvesting period. This study provides valuable information for the development and utilization of L. indica L. cv. Mengzao and determined the best part to harvest and the optimal time for harvesting.

Better quality and odor of silage and normal microbial fermentation metabolism are mostly dependent on an appropriate moisture content. The purpose of this study was to determine the effects of different moisture content gradients (50, 60, 70, and 80%) on the bacterial community, odor, and quality of alfalfa silage at 60 days by using gas chromatography–mass spectrometry (GC–MS) and electronic nose, with six replicates per group. The results showed that there were significant differences in odor response intensity among all groups, among which the 80% group had the strongest reaction to terpenoids, sulfides, and nitrogen oxides. Similarly, the different volatile organic compounds (VOCs) were mainly terpenoids, alcohols, and ketones, such as pine, camphor, and menthol (e.g., carlin and levomenthol). The dominant bacterium was Enterococcus with higher fiber, pH, and ammonia nitrogen (NH₃-N) content but poorer quality and odor (p < 0.05). The differential VOCs in the 60% group were mainly heterocyclics, esters, and phenols with fruity, floral, and sweet odors such as 2-butylthiophene and acorone. Pediococcus and Lactiplantibacillus were the dominant bacteria, with higher crude protein (CP), water-soluble carbohydrates (WSC), and lactic acid (LA) contents, as well as better quality and odor (p < 0.05). The biosynthesis of terpenoids and steroids, biosynthesis of secondary metabolites, and biosynthesis of phenylpropanoids were the main metabolic pathways of differential VOCs. In conclusion, regulating moisture content can alter bacterial community and metabolites, which will encourage fermentation and enhance alfalfa silage quality and odor.

This study aimed to screen and identify lactic acid bacteria (LAB) strains from the Stipa grandis and naturally fermented silage, and assess their effects on the silage quality and bacterial community of Stipa grandis after 60 days of the fermentation process. A total of 38 LAB were isolated, and strains ZX301 and YX34 were identified as Lactiplantibacillus plantarum and Pediococcus pentosaceus using 16S rRNA sequences; they can normally grow at 10−30 °C, with a tolerance of pH and NaCl from 3.5 to 8.0 and 3 to 6.5%, respectively. Subsequently, the two isolated LAB and one commercial additive (Lactiplantibacillus plantarum) were added to Stipa grandis for ensiling for 60 days and recorded as the ZX301, YX34, and P treatments. The addition of LAB was added at 1 × 10⁵ colony-forming unit/g of fresh weight, and the same amount of distilled water was sprayed to serve as a control treatment (CK). Compared to the CK treatment, the ZX301 and YX34 treatments exhibited a positive effect on pH reduction. The water-soluble carbohydrate content was significantly (p < 0.05) increased in ZX301, YX34, and P treatments than in CK treatment. At the genus level, the bacterial community in Stipa grandis silage involves a shift from Pantoea to Lactiplantibacillus. Compared to the CK treatment, the ZX301, YX34, and P treatments significantly (p < 0.05) increase the abundance of Pediococcus and Lactiplantibacillus, respectively. Consequently, the results indicated that the addition of LAB reconstructed microbiota and influenced silage quality. The strain ZX301 could improve the ensiling performance in Stipa grandis silage.

Spirulina (Arthrospira platensis) is rich in a variety of fermentable fibers and prebiotics, which can promote the proliferation of beneficial flora in the intestinal tract of ruminants and optimize the balance of microorganisms in the rumen. The aim of this study was to evaluate whether dietary supplementation with Spirulina has a beneficial effect on the rumen microbial community and serum indices in lambs. For this purpose, 36 lambs with a mean weight of 21.68 kg (standard deviation 1.04 kg) and an age of approximately 5 months (standard deviation 4 days) were selected for the study. The same scale was used for age standard deviation, i.e., 4 days/30.5 days (1 month) = 0.13 months. All lambs were randomly assigned into two treatments, and received non-Spirulina diet as the control (CK treatment) and the Spirulina added diet (Spirulina was added at a rate of 3% of the fresh weight of the diet). The results indicated that the triacylglycerol (p < 0.0001), alanine transaminase (ALT) (p < 0.0001), aspartate aminotransferase (AST) (p < 0.0001), glucose (p < 0.0001), immunoglobulin G (p = 0.0066) and insulin (p = 0.0025) levels were markedly increased in the Spirulina treatment compared to those in the CK treatment. The principal coordinates analysis showed that the bacterial community did not cluster separately between the CK and Spirulina treatments. Firmicutes, Bacteroidetes and Actinobacteria were the dominant members of the community in two treatments. Prevotella were the primary genera, followed by the Lachnospiraceae_NK3A20_group, Olsenella, Succinivibrionaceae_UCG-001 and Ruminococcus, and a significant (p < 0.05) difference was found in Olsenella between the two treatments. These results suggest that the addition of Spirulina is more beneficial for serum biochemical parameters and rumen microbiota of lambs. Overall, these findings contribute to the development of strategies to improve rumen microbial communities for healthy ecosystems on the Mongolian Plateau and provide a scientific basis for the use of Spirulina in feed.

Fermented total mixed ration (FTMR) is an effective approach to preserve low-quality crop residues. This study investigated the effects of ensiling duration (0, 3, 5, 7, 15 and 30 days) on nutritional dynamics, fermentation quality, in vitro digestibility, and bacterial communities of FTMR containing corn stalk and broom sorghum straw at 50% moisture. After 30 d of ensiling, FTMR had the highest crude protein content, lowest neutral detergent fiber content, peak lactic acid concentration, stable low pH, undetectable butyric acid, and maximum in vitro NDF digestibility. Bacterial alpha diversity declined significantly during ensiling, and the community was dominated by Leuconostoc, Lactiplantibacillus, and Levilactobacillus. These results clarify the microbial regulatory mechanism of mixed-straw FTMR fermentation and support the efficient utilization of crop residues in ruminant production.