Table_1_Influence on the fermentation quality, microbial diversity, and metabolomics in the ensiling of sunflower stalks and alfalfa.xlsx

With the rapid development of the livestock industry, finding new sources of feed has become a critical issue that needs to be addressed urgently. China is one of the top five sunflower producers in the world and generates a massive amount of sunflower stalks annually, yet this resource has not been effectively utilized. Therefore, in order to tap into the potential of sunflower stalks for animal feed, it is essential to explore and develop efficient methods for their utilization.In this study, various proportions of alfalfa and sunflower straw were co-ensiled with the following mixing ratios: 0:10, 2:8, 4:6, 5:5, 6:4, and 8:2, denoted as A0S10, A2S8, A4S6, A5S5, A6S4, and A8S2, respectively. The nutrient composition, fermentation quality, microbial quantity, microbial diversity, and broad-spectrum metabolomics on the 60th day were assessed. The results showed that the treatment groups with more sunflower straw added (A2S8, A4S6) could start fermentation earlier. On the first day of fermentation, Weissella spp.dominated overwhelmingly in these two groups. At the same time, in the early stage of fermentation, the pH in these two groups dropped rapidly, which could effectively reduce the loss of nutrients in the early stage of fermentation.In the later fermentation period, a declining trend in acetic acid levels was observed in A0S10, A2S8, and A4S6, while no butyric acid production was detected in A0S10 and A2S8 throughout the process. In A4S6, butyric acid production was observed only after 30 days of fermentation. From the perspective of metabolites, compared with sunflower ensiling alone, many bioactive substances such as flavonoids, alkaloids, and terpenes are upregulated in mixed ensiling.

随着畜牧业的快速发展，寻找新型饲料原料已成为亟待解决的关键问题。我国是全球前五的向日葵生产国之一，年产向日葵秸秆数量庞大，但该资源尚未得到有效利用。因此，为挖掘向日葵秸秆作为动物饲料的应用潜力，探索并开发高效利用该资源的方法至关重要。
本研究将苜蓿与向日葵秸秆按以下比例进行混合青贮：0:10、2:8、4:6、5:5、6:4及8:2，分别记为A0S10、A2S8、A4S6、A5S5、A6S4及A8S2。于青贮第60天，对各组的营养成分、发酵品质、微生物数量、微生物多样性及广谱代谢组学特征进行了测定分析。
结果表明，向日葵秸秆占比更高的处理组（A2S8、A4S6）发酵启动更早。发酵首日，该两组样品中魏斯氏菌属（Weissella spp.）占据绝对优势；同时，发酵早期该两组的pH值快速下降，可有效减少发酵初期的营养物质流失。
发酵后期，A0S10、A2S8及A4S6组的乙酸含量呈下降趋势；且A0S10与A2S8组在整个发酵周期内均未检出丁酸。A4S6组仅在发酵30天后才可检出丁酸。从代谢物层面来看，与单一向日葵秸秆青贮相比，混合青贮组中黄酮类、生物碱类及萜类等多种生物活性物质的表达量显著上调。