Fermentation properties and bacterial community composition of mixed silage of mulberry leaves and smooth bromegrass with and without Lactobacillus plantarum inoculation

To evaluate the fermentation properties and bacterial community composition of mulberry leaves when ensiled with smooth bromegrass, and the effects of Lactobacillus plantarum inoculation on the mixed silage of mulberry leaves and smooth bromegrass, mulberry leaves were mixed with smooth bromegrass at ratios of 100:0, 90:10, 80:20, 70:30 and 60:40, and ensiled for 60 d with and without L. plantarum inoculant. Results showed that the sole fermentation of mulberry leaves failed to achieve optimum fermentation quality. Silage with the ratio of mulberry leaves being 80% performed better fermentation quality compared with other non-inoculated groups, indicated by lower pH value, adequate lactic acid accumulation, and enriched proportion of Lactobacillus in bacterial community. L. plantarum inoculation dramatically improved fermentation quality of mulberry leaf silage compared with the non-inoculated control. However, fermentation quality of the inoculated silage decreased along with the reduction in ratio of mulberry leaves. In conclusion, L. plantarum inoculation has the capability of improving silage quality of mulberry leaves. Combined ensiling with smooth bromegrass could also aid in improving silage quality of mulberry leaves, with the optimum ratio of mulberry leaves being 80%.Key words: mulberry leaves; smooth bromegrass; silage fermentation; absolute quantification 16S-seq