Effects of silage additives on quality and microbial diversity of semi-dry silage of licorice stems and leaves with different moisture content

TANG Limin; LIU Haonan; SUN Yuliang; GAO Qifeng; REN Yulan; JIA Chunying; YU Houjun; JIANG Tao

doi:10.13557/j.cnki.issn1002-2813.2025.11.019

Abstract：The experiment aimed to study the effects of silage additives and moisture content on the fermentation quality of semi-dry silage of licorice stems and leaves.Experiment 1:The stems and leaves of licorice were divided into two groups for silage treatment.Group GJ was silaged with 0.035 g of silage additive,while group GN was silaged without additive.There were six replicates in each group,and the silage lasted for 60 days.Experiment 2:Based on the results of experiment 1,the moisture content was adjusted and a total of six groups were set up.The moisture content of the G65J35 group,G60J40 group,G55J45 group,G50J50 group,G45J55 group,and G40J60 group was 35％,40％,45％,50％,55％,and 60％,respectively,with four replicates in each group,and the silage was 60 days.The results showed that the contents of crude protein(CP),soluble carbohydrate(WSC),lactic acid(LA),acetic acid(AA),and propionic acid(PA)in the GJ group were significantly higher than those in the GN group(P＜0.05),while the ammonia nitrogen/total nitrogen(NH3-N/TN)and pH value were significantly lower than those in the GN group(P＜0.05).The contents of CP and WSC in the G55J45 group were significantly higher than those in the other groups(P＜0.05),and the content of crude Ash(Ash)in the G6.5J35 group and the G55J45 group was significantly higher than that in the other groups(P＜0.05).The sensory grades of silage in G65J35,G60J40,G55J45,and G50J50 groups were excellent,while those in G45J55 and G40J60 groups were relatively good.Among them,G55J45 group had the highest sensory score and better sensory quality.The Simpson index of the G60J40 and G55J45 groups was significantly higher than that of the G45J55 group(P＜0.05),and the Shannon index of the G55J45 group was significantly higher than that of the other groups(P＜0.05).The top 3 dominant bacterial phyla in terms of relative abundance of semi-dry silage of licorice stems and leaves in all experimental groups were Firmicutes,Proteobacteria and Actinobacteriota.The dominant bacterial genus in the G50J50 and the G45J55 groups was Lactobacillus plantarum,while that in the G60J40 group was Lactobacillus lactiflora,and that in the G55J45 group was other bacterial genera.After aerobic exposure,the pH value of the G55J45 group showed a downward trend.On the 15th day of aerobic exposure,the number of molds in the G55J45 group was significantly lower than that in the other groups(P＜0.05),indicating that the G.55J45 group was conducive to the long-term preservation of licorice stem and leaf silage.The study indicates that when the moisture content is 45％,adding silage additives,the semi-dry silage effect of licorice stems and leaves is bettter.