The Potential of Pre-fermented Juice or Inoculants to Improve the Fermentation Quality of Mixed Silage of Agro-Residue and Lucerne.

The objective of this study was to determine the effect of pre-fermented juice, , and . on chemical composition, fermentation, aerobic stability, dynamics of microbial community, and metabolic pathway of a mixture of lucerne, wheat bran (WB), and rice straw (RS). All mixtures were ensiled for 1, 3, 5, 7, 15, 30, and 45 days after treatment with uninoculated (control, C); . [LP, 1 × 10 cfu/g of fresh weight (FW)]; (LB, 1 × 10 cfu/g of FW); LP + LB (LPB, 1 × 10 cfu/g of FW of each inoculant); and pre-fermented juice (J; 2 × 10 cfu/g of FW). Four lactic acid bacteria (LAB) species from three genera were cultured from the pre-fermented juice, with being dominant. The inoculants increased lactic acid (LA), decreased pH and ammonia nitrogen (AN) compared to C silage at earlier stages of ensiling, and high dry matter (DM) and water-soluble carbohydrate (WSC) content in inoculated silages. Adding LPB increased the abundance of , , and , resulting in the lowest pH. Pre-fermented juice enriched , , , , and , mainly enhanced accumulation of acetic acid (AA) and LA, and decreased pH, crude protein losses, AN, and hemicellulose contents. and had a high abundance in LB-treated and J silages, respectively, inhibited undesirable bacteria, and improved aerobic stability with more than 16 days. In addition, the metabolic pathways changed with time and inoculants promoted global metabolism. In conclusion, inoculations altered bacterial succession and metabolic pathways in silage; LB and pre-fermented juice enhanced ensiling by promoting pH reductions, enhancing concentrations of LA and AA, and extending aerobic stability more than 16 days.