Research On The Tolerability And Bacteriostasis Of Enterococcus Faecalis And The Effects On Rumen Fermentation

To study the feasibility of Enterococcus faecalis used as a direct-fed microbials onruminants and the effectiveness of complex-probiotic-preparation containing Enterococcusfaecalis, four experiments were performed on the following aspects using Jinjiang cattlesas model animals:Experiment1: Effects of pH, gastric juice, intestinal juice, bile salt on the tolerabilityof Enterococcus faecalisTo study the effects of pH, gastric juice, intestinal juice, bile salt on the tolerability ofEnterococcus faecalis, the experiment determined the survival rates of Enterococcusfaecalis at different time which treated by different levels of them. The results showed that:（1） the acid tolerance of Enterococcus faecalis was stronger than the base. Especiallystrong base （pH=10） tolerance was much poor;（2） the survival rates of Enterococcusfaecalis treated by bile salt of0.2⁰.4%did not greatly changed. But the survival rates hadbeen influenced greatly by high concentration （0.5%）. And the longer the handling timegrew the more obviously the survival rates decreased;（3） the tolerance of enterococcusfaecalis on rumen liquid was strong. Survival rate was above95%after handling3h. Onthe contraty the tolerance of artificial gastric juice was much poor; Survival rate was only37.93%after3h;（4） Enterococcus faecalis could tolerate artificial intestinal juice for2⁴hours with the survival rate of72.64%. But survival rate decreased obviously after4h.Experiment2: Effect of antibiotics on tolerance of enterococcus faecalis and theinhibition of enteric pathogenic bacteriaThe effect of antibiotics on tolerance of enterococcus faecalis detected by the agardilution method and the inhibition of enteric pathogenic bacteria which using Oxford Cupmethod. The results showed that enterococcus faecalis could tolerate Arsanilic Acid,Bacitracin zinc, Chlortetracycline, Olaquindox and Myxobacterium, but the tolerance toKitasamycin and Salinomycin were relatively worse. In addition, it has slight bacteriostaticaction against Escherichia coli K88but has no bacteriostatic action on Staphylococcusaureus and Salmonella.Experiment3: Effects of complex-probiotic-preparation on rumen fermentation ofJinjiang cattleBatch culture procedure was carried out in vitro, five test teams were designed whichcontained with one control group supplemented none complex-probiotic-preparation, fourtreatment groups supplemented complex-probiotic-preparation Ⅰ,Ⅱ,Ⅲ and Ⅳ respectivelyin basic diet for200mg/kg. Each treatment was cultivated for24hours. The resultsshowed that （1） pH value of the culture medium in each treatment was within the normalrange;（2） Groups supplemented complex-probiotic-preparation Ⅰ,Ⅱ and Ⅲ increased gasproduction significantly compared with the control group（P<0.05）. Especially production in the group of complex-probiotic-preparation Ⅱ is the highest up to170.50ml;（3） MCPproduction in the complex-probiotic-preparation Ⅰ,Ⅱ group significantly improved （P<0.01）, notably complex-probiotic-preparation Ⅱ up to270.43mg/100ml;（4） Compared to thecontrol group and complex-probiotic-preparation Ⅳ group, the NH3-N concentrationdecreased very significantly in group Ⅰ,Ⅱ and Ⅲ （P<0.01）;（5） NDF digestibility in group Iand Ⅱ very significantly improved（P<0.01）;（6） Concentrations of total VFA andPropionate were very significantly increased in group Ⅰ,Ⅱ and Ⅲ compared to the controlgroup（P<0.01）, and group Ⅱ was the highest. But Acetate to Propionate ratio was thelowest （P<0.01）.Experiment4: Effects of diet with different levels of complex-probiotic-preparationon rumen fermentation of jinjiang cattle in vitroThere were five test groups in this experiment, and each treatment with threereplications. Batch culture procedure was carried out in vitro. The control group wasprovided with no complex-probiotic-preparation Ⅱ and other four treatment groups weresupplied with100,150,200and250mg/kg complex-probiotic-preparation Ⅱ respectivelyin basic diet. Each treatment was cultivated for24hours. The results showed that （1） therewas no significant difference in gas production and pH value（P>0.05）, but with thesupplement of complex-probiotic-preparation Ⅱ the gas production showed an increasingtrend and pH value showed a decreasing trend;（2） Compared to the control group, theNH3-N concentration decreased very significantly in the four treatment groups（P<0.01）,especially the treatment which supplied with150mg/kg was the lowest about20.92mg/100ml;（3） MCP production in the200mg/kg group significantly improved （P<0.05）,but had no difference with the150mg/kg group（P>0.05）;（4） Concentrations of total VFAin the200and150mg/kg groups were very significantly higher than other three groups（P<0.01）;（5） Acetate to Propionate ratio showed a decreasing trend after addingcomplex-probiotic-preparation Ⅱ. The200mg/kg group was very significantly lower thanthe control group （P<0.01）, significantly lower than the100and250mg/kg groups（P<0.05）, but had no difference to the150mg/kg group （P>0.05）;（6） The dry matterdigestibility improved after adding complex-probiotic-preparation Ⅱ. The group whichadding150mg/kg significantly improved （P<0.05）, the100and250mg/kg groups’ NDFdigestibility also significantly improved （P<0.05）. Conclusions:complex-probiotic-preparation Ⅱ could improve concentrations of total VFA, NH3-Navailability and MCP production of rumen liquid, in addition, the dry matter digestibilityand NDF digestibility also improved. The adding of complex-probiotic-preparation Ⅱcould improve the roughage’s utilization and the supplementing of150²00mg/kg wasmost suitable.Conclusions:（1） The acid tolerance of enterococcus faecalis was strong, enterococcusfaecalis had high tolerance to gastric juice,intestinal juice, bile salt, and could adapt to the gastrointestinal tract;（2） Enterococcus faecalis could tolerate Arsanilic Acid, Bacitracinzinc, Chlortetracycline, Olaquindox and Myxobacterium;（3） The adding ofcomplex-probiotic-preparation could stabilize the rumen environment,improve theconcentrations of total VFA, NH₃-N availability, MCP production, and the dry matter andNDF digestibility. In short, it improved the roughage’s utilization and rumen fermentation;（4） Complex-probiotic-preparation Ⅱ was beneficial to rumen fermentation of jinjiangcattle and the most suitable supplementing is150²00mg/kg.