添加肠球菌对收获籽实后玉米秸秆青贮品质及体外发酵特性的影响

Effect of adding enterococci on fermentation quality and in vitro fermentation of corn stover silages

[目的]探究两种肠球菌对玉米秸秆青贮饲料发酵品质及体外发酵特性的影响。[方法]试验以收获玉米果穗后的玉米秸秆为青贮原料,设对照、蒙氏肠球菌(Enterococcus mundtii)和粪肠球菌(E.faecalis)添加3个处理,乳酸菌添加量为5log cfu·g-1FW,青贮45d后取样分析青贮饲料发酵品质,并利用体外产气法测定青贮饲料鲜贮发酵特性。[结果]添加两种肠球菌显著降低了青贮饲料氨态氮和乙酸含量(P<0.05),显著提高了乳酸/乙酸比率(P<0.05),并提高了青贮饲料体外发酵潜在产气量、发酵液挥发性脂肪酸产量(P<0.05)及乙酸比例(P<0.05)。[结论]添加两种肠球菌对玉米秸秆青贮饲料发酵品质和体外发酵均具有一定的改善作用。

[-Objective] This study was to investigate the effect of adding enterococci on fermentation quality and in vitro fermentation of corn stover silages. [-Methods] The treatments were as follows： control, E. mundtii and E. faecalis, the levels of each lactic acid bacteria inoculation were determined at 5 log cfu·g-1 FW （fresh weight）. Corn stover was the residue remaining after grain was harvested. Five reduplicate silos per treatment were opened on 45 days after ensiling and the fermentation quality was analyzed. The rumen fermentation characteristics of fresh silage were determined by in vitro gas production method. [-Results] Compared to control silage, corn stover inoculated with E. mundtii or E. faecalis had significantly lower ammonia nitrogen and acetate acid contents （P〈0.05）, higher ratio of lactic acid to acetic acid （P〈0.05）, and higher potential gas production, total VFA concentration （P〈0.05） and acetate acid pro- portion （P〈0.05） of ruminal fermentation liquid. [Conclusion] In conclusion, it was suggested that addition of En- terococcus species improved the fermentation quality and in vitro fermentation of corn stover silages.