Abstract: The experiment aimed to study the fermentation quality of oat silage and the dynamic changes of bacterial communities in the higher-cold and cloudy-humid region of central Gansu and provide a basis for the utilization of oats as high-quality silage. The whole oat plants at milk stage was used for vacuum silage， and fermented at natural temperature （6-12℃）. The samples were taken at 0 d， 3 d， 7 d， 14 d and 30 d after fermentation， and the nutritional components， fermentation quality and bacterial community characteristics were determined and analyzed. The results showed that with increasing fermentation time， soluble carbohydrates decreased by 55.52% from day 0 to day 30； neutral detergent fiber and acid detergent fiber contents significantly decreased （P<0.05） from day 7 to day 30， reducing by 10.25% and 6.23%， respectively， from day 0 to day 30； the pH value dropped to 4.15. The levels of lactic acid， acetic acid， and propionic acid significantly increased （P<0.05）， while butyric acid was undetectable in all samples. As fermentation time extended， bacterial community species richness initially increased and then decreased， with dominant phyla shifting from Proteobacteria and Cyanobacteria to Firmicutes. Dominant genera transitioned from Rosenbergiella and Pantoea to Lactiplantibacillus. By day 7 of ensiling， Lactiplantibacillus became the dominant genus， accounting for an average of 44.78% of total genera. Bacterial richness peaked at day 14 of ensiling. Genera such as Lactiplantibacillus and Levilactobacillus， which are beneficial microorganisms， are key microbial components influencing oat silage quality， significantly affecting nutritional content and fermentation indicators.

Key words: Oat silage, Quality, Bacterial community, Dynamics

摘要： 试验旨在研究陇中华家岭二阴区燕麦青贮发酵品质及细菌群落动态变化，为燕麦高品质青贮利用提供依据。以乳熟期燕麦全株为原料进行真空青贮，自然气温（6~12℃）下发酵，在发酵第3 d，7 d，14 d，30 d开袋取样，测定并分析营养成分、发酵品质及细菌群落特征。结果表明，随着发酵时间的延长，可溶性碳水化合物在青贮30 d较0 d降低了55.52%；中性洗涤纤维和酸性洗涤纤维含量在青贮7~30 d显著下降（P<0.05），青贮30 d时较0 d分别降低了10.25%和6.23%；pH值下降至4.15；乳酸、乙酸及丙酸含量显著增加（P<0.05），丁酸含量在各样品中均未检测到。随着发酵时间的延长，细菌群落物种丰富度先增加后减少，优势菌门由变形菌门（Proteobacteria）和蓝细菌门（Cyanobacteria）演变为厚壁菌门（Firmicutes），优势菌属由罗森伯氏菌属（Rosenbergiella）、泛菌属（Pantoea）等演变为植物乳杆菌属（Lactiplantibacillus），且青贮7 d时，植物乳杆菌属成为优势菌属，平均占总属类的44.78%，青贮14 d时的细菌丰富度达到高峰。植物乳杆菌属、促生乳杆菌属（Levilactobacillus）等有益微生物是影响燕麦青贮品质的核心微生物组分，显著影响营养成分和发酵指标。

关键词: 燕麦青贮, 品质, 细菌群落, 动态