Effects Of Cellulase And Lactiplantibacillus Plantarum On The Fermentation Quality,Bacterial Flora And In Vitro Rumen Fermentation Parameters Of Caragana Korshinskii Silage

In the present study,we investigated the effects of cellulase and Lactiplantibacillus plantarum(L.plantarum)on the fermentation quality,microbial diversity,gene function prediction,and in vitro rumen fermentation parameters of the Caragana korshinskii(C.korshinskii)silage.The experimental treatment groups included control(CK),cellulase(C),L.plantarum(L),and cellulase+L.plantarum(CL).Triplicate silos were sampled after 14 and 56days of ensiling.The microbial diversity of C.korshinskii silage at 56 days was analyzed using Illumina Mi Seq sequencing technology,and the effects of C.korshinskii silage on rumen fermentation were evaluated by the in vitro artificial rumen gas production method.The results showed that the addition of cellulose and L.plantarum treatments reduced ammonia-nitrogen,dry matter,neutral detergent fiber,and acid detergent fiber content during ensiling(P<0.05).Compared with the CK group,higher lactic acid content was observed in the silage of the C and L groups(P<0.05),but the CL group had a higher acetic acid content(P<0.05).Compared with the CK group,the relative abundance of Lactobacillus significantly increased,but that of Enterococcus,Weissella,Enterobacter,and Pediococcus significantly decreased in all other groups except the C group(P<0.05).The results of gene function prediction were as follows:pyruvate kinase,1-phosphofructokinase,and fructokinase were lactate production enzymes,which suggested the association of the high acetic acid content in the CL group to the high abundance of 6-phosphate glucose dehydrogenase.The abundance of H~+-transporting ATPase and ABC transporters in the L and CL groups was higher than that in the CK groups.Metabolism of terpenoids and polyketides,mismatch repair,DNA replication,nucleotide excision repair,and homologous recombination increased in the CL group compared with those in the CK group.The results of rumen fermentation in vitro showed that compared with the CK group,ammonia nitrogen and microbial protein content and the degradation rates of dry matter and neutral detergent fiber degradation increased in the L and CL groups(P<0.05).In conclusion,the addition of cellulase and Lactiplantibacillus plantarum can improve the fermentation quality of C.korshinskii silage,increased the abundance of beneficial bacteria Lactobacillus,and decreased the abundance of harmful bacteria Enterobacter,and also increased rumen dry matter,neutral detergent fiber and acid detergent fiber degradation rate and microbial protein content.In general,the effect of adding cellulase+Lactiplantibacillus plantarum was better in C.korshinskii silage,which could provide a theoretical basis for improving the quality of silage.