Influence of Cellulase or on the Ensiling Performance and Bacterial Community in Mixed Silage of Alfalfa and .

The objective of this study was to evaluate the effects of or cellulase on the fermentation characteristics and bacterial community of mixed alfalfa ( L., AF) and (LC) silage. The harvested alfalfa and were cut into 1-2 cm lengths by a crop chopper and they were thoroughly mixed at a ratio of 3/2 (wet weight). The mixtures were treated with no addition (CON), (LP, 1 × 10 cfu/g fresh material), cellulase (CE, 7.5 × 10 U/kg fresh material) and their combination (LPCE). The forages were packed into triplicate vacuum-sealed, polyethylene bags per treatment and ensiled for 1, 3, 5, 7 and 30 d at room temperature (17-25 °C). Compared to the CON groups, all the additives increased the lactic acid content and decreased the pH and ammonia nitrogen content over the ensiling period. In comparison to the other groups, higher water-soluble carbohydrate contents were discovered in the CE-inoculated silages. Compared to the CON groups, the treatment with LPCE retained the crude protein content and reduced the acid detergent fiber content. The principal coordinate analysis based on the unweighted UniFrac distance showed that individuals in the AF, LC, CON and LPCE treatment could be significantly separated from each other. At the genus level, the bacterial community in the mixed silage involves a shift from to . dominated in all the treatments until the end of the silage, but when added with it was more effective in inhibiting undesirable microorganisms, such as , while reducing microbial diversity. By changing the bacterial community structure after applying and cellulase, the mixed silages quality could be further improved. During ensiling, the metabolism of the nucleotide and carbohydrate were enhanced whereas the metabolism of the amino acid, energy, cofactors and vitamins were hindered. In conclusion, the relative abundance of in the mixed silage increased with the addition of and cellulase, which also improved the fermentation quality.