Study On Quality Of Corn Silage By Synergistic Effect Of Cellulose Decomposing And Lactic Acid Bacteria Colony

Objective:In this study,silage corn was fermented by using cellulose decomposition bacteria（CDB）and different fermentation types lactic acid bacteria（LAB）as multiple species inoculant in order to improve quality and reduce nutrient consumption by using the synergistic effect between bacteria.Method:First of all,the response surface optimization method was used to optimize the proportion and dose of fermentative bacteria,and then in for silage corn fermentation,three types of fermentation treatment combination were designed totally.Secondly,the silage corn was fermented according to the optimization results,a total of 3 types of fermentation treatment were designed.Category 1:Controlled treatment（K）,2 homofermentative LABs mixed with 1:1（T）,CDB+T（TX）;Category 2:K,heterofermentative LAB（Y）,CDB+Y（YX）;Category 3:K,the homo-and heterofermentative LAB（TY）,CDB+TY（TYX）,which homofermentative LAB was Lactobacillus plantarum（ACCC 11016）and Pediococcus acidilactici（ACCC 05481）(addition 1:1,5×10⁵ cfu/g),heterofermentative LAB was Lactobacillus buchneri（CICC 20293）(5×10⁵ cfu/g),the CDB were Aspergillus niger（ACCC 30134）,Trichoderma viride（ACCC 30595）and Bacillus subtilis（ACCC 19374）（addition content 2:1:1,0.3%）.Major microbes population,fermentation products,nutrients,enzyme production,as well as aerobic stability（AS）and in rumen semi-external digestion were analyzed in corn silage fermentation（within 60 days）and during open pit（within 10 days）.Mainly get the following results.Results:（1）The all treatment and fermentation time affected significantly the 4 kinds of microorganisms number during fermentation.In the open pit;the 4 kinds of microorganisms number treated with TX,YX,TYX treatment were significantly higher than added T,Y or TY treatment alone.The treatment of YX and TYX did not affect the ethanol content,and all treatment did not affect the acetic acid（AA）content,the other fermentation treatments could affect significantly the fermentation characteristics of corn silage during fermentation.In addition to the TYX treatment did not affect the cellulose content obviously,the other treatments could affect significantly nutrients of the corn silage during fermentation.The treatments of YX,TYX could affect significantly the hemicellulase activity（HA）in corn silage during fermentation.After the open pit;The all fermentation treatment affected significantly the number of yeast and mold,and the days of open pit also affected significantly the number of LAB,yeast and mold.The treatment of TX,TYX affected the content of the fermented characteristic matter,except the water soluble sugar（WSC）,lactic acid（LA）and AA content,and treatment of YX affect significantly the WSC and AA content after the open pit.The all fermentation treatment could affect significantly the CO₂ content of silage,but could not affect the AS time.The treatment of TX,YX could significantly affected the contents of dry matter（DM）,acid detergent lignin（ADL）and hemicellulose（HE）,the treatment of CDB+TY mainly affected the neutral detergent fiber（NDF）,crude fiber（CF）and crude fat（EE）content.The treatments had significant effects on the activity of amylase in period of fermentation and open pit,except that the treatment of TYX had no significant effect on the amylase activity.（2）In this study,all the identified species were divided into 13 genera and 51 species,which were named Lactobacillus sp.,Citrobacter sp.,Leuconostoc sp.,Escherichia coli sp.,Escherichia sp.,Klebsiella sp.,Asticcacaulis sp.,Pantoea sp.,Obesumbacterium sp.,Serratia sp.,Salmonella sp.,Shigella sp.and Cedecea sp.,respectively.（3）As the fermentation time;the optimal fitting model of the number of aerobic bacteria（AB）was Polynomial model,the LAB was the Linear model,the yeast was the Allometric model and the mold was Logistic model.During fermentation;the pH was mainly affected by the synergistic effect of yeast and mold,the LA,crude protein（CP）,crude ash（CA）content and HA were mainly affected by the LAB and mold synergistic effects,The DM,starch,acid detergent lignin（ADL）,AA,ammonium-nitrogen（AN）content and the ratio of AN and total nitrogen（TN）were chiefly affected by LAB,the ethanol content was affected by AB and yeast synergistic effect,the EE content was affected by the synergistic effect of yeast and mold.During fermentation;increasing the HA reduced the content of WSC,starch and ADL significantly,improve the activity of amylase could increase the WSC,starch,ADL,HE content,and reduce the CF content distinguished.As the time of open pit time;the optimal model of the number of AB was Gaussian model,the LAB and the yeast were Logistic model and the mold was Allometric model.After the open pit;the content of AA and the HA were mainly affected by AB number,the DM content was chiefly affected by the population of yeast.The CP content was mainly affected by the number of molds,the EE content was affected by LAB,and the synergistic effect of 4 kinds of microorganisms was obviously effect NDF,CF,CA,AN content,pH and the ratio of AN and TN.Increased HA significantly reduced starch,NDF,ADF and CF content after the open pit.（4）The treatment of TX significantly affected the acid detergent fiber digestibility（ADFD）and the organic matter digestibility（OMD）.The treatment of TYX affected the dry matter degradation（DMD）,ADFD,OMD obviously.The treatment of TX affected the degradation characteristics of organic matter rapid degradation part（a）,slow degradation part（b）and potential degradation part（a+b）obviously.The treatment of YX significantly affected effective degradability（ED）of DM and degradation rate of slow degradation（c）.The treatment of YX affected a,b,a+b,ED of DM,c of NDFD,a and a+b of ADFD,b of OMD.The DMD optimal degradation model was Logistic model,the NDFD was Logistic model,the ADFD was Logistic model and the OMD was Allometric model.Conclusion:In the case of composite fermentation,the effect of CDB and heterofermentative LAB compound fermentation was better in 60 d of fermentation,which improved the quality of silage corn and feed value.The combined value of principal component analysis results were as follows:T>YX>TY>TX>CK>Y>TYX.The results provided a favorable basis for solving the problem of feed shortage in China and a theoretical basis for the development of new biological silage additives in China.