Effects Of Lactobacillus And Cellulase On The Quality Of Italian Ryegrass And Maize Straw Mixed Silage

The Italian ryegrass（Lolium multiflorum Lam.）and Maise straw were the raw material to explore the dynamic effect on fermentation process of two storage proportion of 10:0（S0）and 7:3（S1）and three different addictives which were Lactobacillus plantarum,Lactobacillus buchneri and cellulase.Six treatments were organised in this study which contained control,B（Lactobacillus buchneri）,BC（Lactobacillus buchneri+cellulase）,P（Lactobacillus plantarum）,PC（Lactobacillus plantarum+cellulase）andBPC（Lactobacillus plantarum+Lactobacillus buchneri+cellulase）to analyse the dynamic effects on p H degree,fermentation quality,V-score,nutritional quality,recovery rate of dry matter（DMR）and microbiological composition,which were under the different addictives and ensiling periods of 3d,7d,21d,42d,75d,105d.The results were shown below.1.The fermentation quality of the silageDifferent additives influenced p H degree and fermentation quality of the silage,significantly（P<0.05）.The p H degree,the ratio of ammoniacal nitrogen/total nitrogen（NH₃-N/TN）,volatile fatty acid（VFA）of S0 was higher than S1 and the V-score was 12.42 after ensiled 105 days.The p H degree of S0BPC dropped to the lowest to 4.2after ensiled 7 days and increased to 4.7 after ensiled 105 days,the content of lactic acid（LA）and acetic acid（AA）was higher than S0,the content of PA,BA and NH₃-N/TN were significantly lower than the treatment of Lactobacillus plantarum,but they were higher than the treatment of Lactobacillus buchneri,the V-score was 43.71 and the silage corrupted seriously after ensiled 105 days.The p H degree,NH₃-N/TN and the content of VFA were significantly higher than other treatments,the content of AA was siginificantly higher than other treatments and the V-score was 81.83,the fermentation quality was good.The p H degree of S1BC dropped to the lowest to 4.7 after ensiled 42d and the content of PA,BA and NH₃-N/TN were significantly lower than other treatments,the content of AA was significantly higher than other treatments,the V-score was 78.66.The p H degree of S1BPC dropped to the lowest 4.7 after ensiled 75 days.After ensiled 105 days,the PA,BA and NH₃-N/TN was significantly lower than other treatments.In the whole process of ensiling,the LA content was the highest,the content of AA was lower than the treatment of Lactobacillus buchneri,the V-score was 83.12,witch can be modulated well.2.The chemical components and recovery of dry matter（DMR）of the silageDifferent additives influenced the chemical components and the recovery of dry matter significantly（P<0.05）.After ensiled 105 days,the content of water soluble carbohydrates（WSC）,dry matter（DM）and crude protein（CP）of S0 was siginificantly lower than S1,the content of acid detergent fiber（ADF）and neutral detergent fiber（NDF）of S1 was significantly higher than S0.The DMR was 52.41 witch was better than S0PC and S0.The content of WSC,DM of S0BPC was significantly higher than S0,the DMR was 49.81.The content of DM of S1PC increased significantly and the content of WSC,NDF and ADF reduced significantly,the DMR was 72.07%and the silage was preserved well.The content of DM,WSC and CP of S1BC was increased significantly while the content of ADF,NDF were reduced significantily and the DMR was 77.11%,the silage was preserved well.The content of DM,CP of S1BPC was increased significantly while the content of WSC,NDF and ADF was reduced significantly,the DMR was 77.74%,the silage was preserved well.3.The dynamic change of microorganisms composition of the silageThe number of lactic acid bacteria and yeast of each treatment showed the trend of increasing firstly then decreased and the number of clostridium showed the increasing trend.When the proportion was 7:3,the changing trend of the amount of lactic acid bacteria and clostridium was light while the number of yeast showed a trend of decline.In the whole process of ensiling,the number of lactic acid bacteria of S0PC reached the peak after fermented 21 days,the number of yeast was the highest after fermented 7 days while the number of clostridium was the lowest,the number of yeast,lactic acid bacteria was reduced to 10⁴ CFU/g and the number of clostridium increased to 10⁶CFU/g with the extension of ensiling period.The number of lactic acid bacteria and yeast of S1P and S1PC reached the peak after preserved 7 days,witch were gradually decreased to 10⁶ CFU/g and10²CFU/g,the trend of the number of clostridium changed lightly.The number of lactic acid bacteria of S1BPC maitained the original account of 10⁸ CFU/g between 7 and 75days of fermentation.while the number of clostridium changed lightly from 3 to 75 days of fermentation and the number of yeast reduced from 10⁶ CFU/g to 10² CFU/g.To sum up,when the proportion of Italy ryegrass and Maise straw was 10:0,the additives worked well before three weeks of fermentation.However,it showed bad quality and enormous nutrient loss after ensiled 105 days.When the ratio of Italy ryegrass and Maise straw was 7:3,the additives played a good role in the whole fermentation process.The Lactobacillus plantarum and Lactobacillus plantarum+celluase generated lactic acid quickly in the early stage of the fermentation and reduced the p H degree of the silage and maintained until the later stage of fermentation,the amount of clostridium,yeast and the content of VFA and NH₃-N/TN was lower and the loss of nuritional composition was small.When the three additives were mixed to use,the silage showed the large amount of lactic acid bacteria and small number of harmful bacteria,good fermentation quality and high level of the content of DM,WSC and CP,the less content of fiber and the DMR was higher,witch was better compared with other treatments.Therefore,taking into consideration of regional climate condition comprehensively and combining with the actual practice in south China,we suggested that the ratio of 7:3 witch was combined a mixture of the three additives can produce high-quality silige of Italy ryegrass.S1P can be popularized and utilised futher because of better fermentation quality and less loss of nutrition when the cellulase was removed.