Ensiling native grass is an effective method to protect the nutritional quality of forage and alleviate feed shortages in the cold winter of the Inner Mongolian Plateau. To improve the usability of native grass resources as feed in China, the effects of lactic acid bacteria and molasses additions on the microbial population, fermentation quality, and nutritional quality of native grass during silage were investigated. Treatments were a control treatment with no additive (CK), lactic acid bacteria (L), molasses (M), and lactic acid bacteria in combination with molasses (L+M), all of which were stored at ambient temperature (17–28°C) for 7, 14, 30, and 60 days. The results showed that all additives improved nutritional value and fermentation quality with low pH and ammonia nitrogen (NH3–N) and high crude protein (CP) and water soluble carbohydrate (WSC) than control silage over the ensiling period. Compared with L or M silage, the L+M silage combination improved fermentability, as evidenced by higher LA content and a faster pH drop during the first 7 days of ensiling. With prolonged ensiling time, the combined addition of L and M could increase the count of desirable Lactobacillus, decrease microbial diversity, and inhibit the growth of undesirable microorganism, such as Clostridia, Escherichia, and Enterobacter abundance compared with silage treated with CK, L. or M. Application of L together with M could further improve the silage quality of native grass by altering bacterial community structure. In summary, the addition of lactic acid bacteria and molasses increased the relative abundance of Lactobacillus of native grass silage and improved fermentation quality.

In this study, we analyzed the fermentation quality, microbial community, and metabolome characteristics of ryegrass silage from different harvests (first harvest-AK, second harvest-BK, and third harvest-CK) and analyzed the correlation between fermentative bacteria and metabolites. The bacterial community and metabolomic characteristics were analyzed by single-molecule real-time (SMRT) sequencing and ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS/MS), respectively. After 60 days of ensiling, the pH of BK was significantly lower than those of AK and CK, and its lactic acid content was significantly higher than those of AK and CK. Lactiplantibacillus and Enterococcus genera dominate the microbiota of silage obtained from ryegrass harvested at three different harvests. In addition, the BK group had the highest abundance of Lactiplantibacillus plantarum (58.66%), and the CK group had the highest abundance of Enterococcus faecalis (42.88%). The most annotated metabolites among the differential metabolites of different harvests were peptides, and eight amino acids were dominant in the composition of the identified peptides. In the ryegrass silage, arginine, alanine, aspartate, and glutamate biosynthesis had the highest enrichment ratio in the metabolic pathway of KEGG pathway enrichment analysis. Valyl-isoleucine and glutamylvaline were positively correlated with Lactiplantibacillus plantarum. D-Pipecolic acid and L-glutamic acid were positively correlated with Levilactobacillus brevis. L-phenylalanyl-L-proline, 3,4,5-trihydroxy-6-(2-methoxybenzoyloxy) oxane-2-carboxylic acid, and shikimic acid were negatively correlated with Levilactobacillus brevis. In conclusion, this study explains the effects of different harvest frequencies on the fermentation quality, microbial community, and metabolites of ryegrass, and improves our understanding of the ensiling mechanisms associated with different ryegrass harvesting frequencies.

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.