Abstract: The objective of this study was to explore the effects of Lactobacillus buchneri and formic acid on the fermentation quality and bacterial community of oat silage at the Tibetan Plateau. Oats (Avena sativa L.) at flowering stage,milk maturity stage and wax maturity stage were used as ensiling materials,and treated without (control) or with additives (formic acid and Lactobacillus buchneri,respectively).We used the samples which were ensiled for 90 days to measure and analyze the nutritional composition,fermentation profile and bacterial community. The results showed that the treatments of Lactobacillus brucei and formic acid both changed their bacterial community compositions (P<0.05),and increased the abundance of Lactobacillus. Compared with the control,when the silage oat was treated with Lactobacillus brucei and formic acid at different stages,the pH of oat during wax maturity stage was significantly reduced (P<0.05),the acetic acid was both increased by 9.7%,propionic acid decreased by 11.6% and 8.6%,and ammonia nitrogen by 11.3% and 19.2%,respectively. When bacterial community composition,fermentation quality and nutritional composition were considered together,the oat at wax maturity stage has better silage quality after adding Lactobacillus buchneri and formic acid.

Key words: Oats, Stages, Qinghai-Tibet Plateau, Silage, Fermentation quality, Bacterial community

摘要： 为探讨布氏乳杆菌和甲酸对青藏高原不同物候期燕麦（Avena sativa L.）青贮饲料发酵品质和细菌群落的影响，本试验以开花期、乳熟期和蜡熟期燕麦为原料，设置对照、添加甲酸和添加布氏乳杆菌3个处理，青贮90 d后，测定其营养成分、发酵指标和细菌群落组成。结果表明：布氏乳杆菌和甲酸处理均改变不同物候期燕麦青贮饲料中细菌群落组成（P<0.05），并提高其乳酸细菌相对丰富度；与对照相比，用布氏乳杆菌和甲酸处理不同物候期的燕麦青贮后，蜡熟期的燕麦pH值降低（P<0.05），乙酸均增加9.7%，丙酸分别降低11.6%和8.6%，氨态氮分别降低11.3%和19.2%。综合细菌群落组成、发酵品质和营养成分来看，蜡熟期的燕麦添加布氏乳杆菌和甲酸后，其青贮品质较佳。

关键词: 燕麦, 物候期, 青藏高原, 青贮, 发酵品质, 细菌群落