Comparative effects of fibrolytic additives combined with Lactobacillus plantarum on fermentation quality, lignocellulose degradation and bacterial community of Siberian wildrye silage

This work aimed to assess the regulatory impacts of three fibrolytic additives on the fermentation quality, lignocellulose degradation, and microbial community of Siberian wildrye silage. Siberian wildrye ( Elymus sibiricus ) was ensiled with Lactobacillus plantarum (CON), formic acid + L. plantarum (ALp), fibrolytic enzymes + L. plantarum (ELp), and fibrolytic microbial consortium + L. plantarum (MLp). All silages were stored at a room (20 ± 3℃) temperature for 50 days with three replicates per treatment. The DM (483 g/kg FW) and WSC (37.1 g/kg DM) contents of ALp were the highest and the AN (17.2 g/kg TN) was the lowest. ELp outperformed all other treatments in terms of hemicellulose degradation rate (18.8%) and total lignocellulose degradation rate (13.3%). MLp had the highest relative abundance of LAB, which contributed to more stable bacterial community structure. The result of co-occurrence network analysis proved that MLp showed both the highest negative/positive correlation ratio and the highest relative abundance of LAB. In this work, ALp achieved the optimal nutrient retention, ELp presented the greatest lignocellulose degradation, while MLp promoted heterofermentative pathways and significantly improved the bacterial community stability.