Effect of Added Composite Bacteria on Fermentation Quality and Microbial Diversity of Mixed Microstorage of Reed Straw and Inferior Jujube

Reed straw is a potential roughage resource that limits its application in livestock production due to its higher fiber content. Inferior jujube is widely used as a non-conventional feed in livestock production due to its high nutritional value. In this study, a two-factor experimental design was used to investigate the effects of fermentation with Composite A (BA) and Composite B (BB) under the condition that the dry matter ratio of reed straw to residual red dates was 1:1, and mixed microstorage was fermented for different times (0 d, 30 d, and 60 d) with the effects of nutrient indexes, fermentation quality, and microbial community dynamics changes. A control group (CON) was set up, six replicates were set up for each treatment, and the amount of bacteria added was 1% of the dry matter basis. The results showed that compared with the control group, both composite bacterial liquids could effectively reduce the nutrient loss of micro-silage feeds, in which with the addition of composite bacterium B (BB) treatment group at the end of fermentation, the crude protein (CP) content increased by 1.91%, and the neutral detergent fiber (NDF) and the acid detergent fiber (ADF) were reduced by 11.32% and 10.61%, respectively. The volatile fatty acid content was significantly higher than that of the control group, which was 26.41 μg·mL−1. The BB group had the highest abundance of Lacticaseibacillus during the fermentation process, which could produce a large amount of lactic acid and lower the pH to improve the quality of feed fermentation. In addition, the differences in the indexes were smaller in the BB group compared with the BA group, but the fermentation effect of the BB group was better than that of the BA group.