Effect of exogenous microorganisms on the fermentation quality, nitrate degradation and bacterial community of sorghum-sudangrass silage.

This study aims to investigate the effects of adding (LB), (LBR) and (BS) on the fermentation quality, nitrate degradation and bacterial community of sorghum-sudangrass silage. The results showed that the addition of LB significantly increased the pH and acetic acid content ( < 0.05), but high-quality silage was obtained. The addition of LBR and BS improved the fermentation quality of sorghum-sudangrass silage. The use of additives reduced the nitrate content in sorghum-sudangrass silage. The LB group increased the release of NO at 3-7 days of ensiling ( < 0.05), and LBR and BS increased the release of NO at 1-40 days of ensiling ( < 0.05). On the first day of ensiling, all silages were dominated by , over 3 days of ensiling all silages were dominated by . , , and showed significant negative correlations with nitrate degradation during sorghum-sudangrass ensiling ( < 0.05). The BS and LBR groups increased the metabolic abundance of denitrification, dissimilatory nitrate reduction, and assimilatory nitrate reduction ( < 0.05). Overall, the additive ensures the fermentation quality of sorghum-sudangrass silage and promotes the degradation of nitrate by altering the bacterial community.