| The tetraploid black locust has been widely planted in China and is well accepted as an important new source of high-protein fodder.Preparation of tetraploid black locust silage not only preserves the original nutritional ingredients of fresh plants but also expands the fodder resource and maintains a year-round supply of succulent food for livestock,meeting the nutritional needs of livestock in winter and spring.The objective of this study was to investigate effects of fermentative substrate and lactic acid bacteria inoculants on fermentation quality,in vitro digestibility and aerobic stability of tetraploid black locust.1.Effects of different level of glucose on the fermentation quality of tetraploid black locustIn order to investigate the effects of different level of glucose on the fermentation quality of tetraploid black locust and evaluate the appropriate level of glucose in silage,the treatments were prepared as follow:no additives(control),2%,3%and 4%glucose.Silos were opened after ensiling 30 d,respectively,and the fermentation quality was analyzed.The result showed that as the glucose level increased,the contents of lactic acid,dry matter and water soluble carbohydrate increased while the pH value and AN/TN decreased.And there was no obvious difference between 3%and 4%(P>0.05).From an economic viewpoint,3%glucose is the most appropriate.2.Effects of glucose,molasses and lactic acid bacteria inoculant on fermentation quality and in vitro digestibility of tetraploid black locustThe objective of this study was to investigate effects of glucose,molasses and inoculant on the fermentation quality of tetraploid black locust.The treatments were as follow:no additives(control),glucose(G),molasses(M),inoculant(L.plantarum)(L),inoculant(L.plantarum)+ glucose(L+G),inoculant(L.plantarum)+ molasses(L+M).The silos were sampled on 7,14,30 and 60 d after ensiling,and the fermentation quality of silages was analyzed.Based on the results,a slow accumulation of lactic acid and decline of pH were observed in tetraploid black locust silage,resulting in low lactic acid(3.32?18.39 g kg-1 DM),acetic acid(16.78?28.81 g kg-1 DM)contents and high pH value(4.88?5.61)at the end of ensiling.However,all treatments were only with minor propionic acid and butyric acid contents(<2 g kg-1 DM)and low ammonia nitrogen/total nitrogen(54.76?60.54 g kg-1 TN).G,M and L silage had no significant effect on fermentation quality compared with control silage.The combined treatments(L+M and L+G)performed better than the single ones(G?M and L),and L+M silage had the highest(P<0.05)lactic acid and lowest(P<0.05)pH value.All additives improved the in vitro digestibility of all treatment,L+M performed best.From the facts mentioned above,L+M group performed best.3.Effects of inoculation of local lactic acid bacteria stains and glucose on the fermentation quality and in vitro digestibility of tetraploid black locustThe purpose of this study was to investigate and evaluate the effect of local lactic acid bacteria stains on the fermentation quality and in vitro digestibility of tetraploid black locust.The treatments were as follow:control(CK),glucose(GL),commercial L.plantarum-MTD1(MTD1),L.plantarum-G7(G7)and L.paraplantarum-15(I5).All the lactic acid bacteria strains were inoculated on the basis of 3%glucose.These silos were sampled on 1,3,5,7,14,30,60 and 90 d after ensiling and the fermentation quality was analyzed.And the in vitro digestibility of 90 d silage was analyzed.Results showed that the lactic acid content and pH value of GL silage had no significant difference with the control.MTD1,G7 and 15 silage produced large amount of lactic acid and decreased the pH at the early stage of the silage,and the content of lactic acid was up to 67.61?71.89 g kg-1 DM at 14 d which was nine fold of the GL and CK silage,resulting in lower pH value,ammonia nitrogen/total nitrogen value,propionic acid contents as well as higher lactic acid,dry matter and water soluble carbohydrate,crude protein,acid and neutral detergent fiber contents compared with control and GL silage(P<0.05),indicating that fermentation quality of these silages were all well.After 72h incubation,MTD1,G7 and 15 silage improved in vitro digestibility significantly(P<0.05)compared with the control.4.Effects of Lactobacillus buchneri and local lactic acid bacteria strains on the fermentation quality,in vitro digestibility and aerobic stability of tetraploid black locustThe aim of this study was to investigate and examine the effect of Lactobacillus buchneri and local lactic acid bacteria(LAB)stains on the fermentation quality,aerobic stability and in vitro digestibility of tetraploid black locust.The treatments were as follow:control(CK),glucose(GL),L.buchneri + commercial L.plantarum-MTD1(BMTD1),L.buchneri + L.plantarum-G7(BG7)and L.buchneri + L.paraplantarum-I5(BI5).All the LAB strains were inoculated on the basis of 3%glucose.These silos were opened atl,3,5,7,14,30,60 and 90 d after ensiling and the fermentation quality was analyzed.And the in vitro digestibility of silage was analyzed after 90 d ensiling.Meanwhile,we evaluated the aerobic stability of the CK,B,BMTD1,BG7 and BI5 silage,which were exposed to the air for 4,8 and16 days.The pH value of BMTD1,BG7 and BI5 silage decreased to 4.2 at 60 d,while CK,GL and B silage maintained high pH value throughout the ensiling period.The in vitro dry matter digestibility and gas production of BMTD1 were the highest(P<0.05).During the aerobic exposure,the CK silage has the most inferior aerobic stability indicated by a rapid increase in pH and the temperature that was more than 2 ? above the environment temperature after 293.5 h.There were only little increase in the pH value of B,BMTD1,BG7 and BI5 silage.All these silages were well preserved during the aerobic exposure period after exposed to the air for 16 d.In conclusion,BMTD1,BG7 and BI5 silage all performed well on fermentation quality and aerobic stability. 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