| Animal microecologcial modulalcr are live microorganic agents with the normal microflora. It can exert very important functions through following mechanisms:dominant microbial flora,colonization resistance,improvement of ecological environment and adjustment for microflora balance,production of antibacterial substances,strengthening epithelial barrier and enhancement of immunity of functions,etc. A lot of tests and practical applications have proved that animal microecollogics can not only improve animal product performance but also have functions on prevention and control the bacteriogenous disease in intestine tract. In this paper .based on the microecological principle,we researched and produced a multi-modulater of Closlridium hudyriciim which including Clostridium hutryricums. Lactic acid bacterias and Yeasls.In this thesis,19 strains of Lactic acid haclcria were isolated from the intestine tract of poultry and swine,five strains were obtained from plate by primary screening,a strain was obtained from further screening. Among the bacteriums,Laclobacilhts strain L-13 has great growth rate and powerful ability of producing lactic acid. Then,by identifying,it was shown to be the characterization of Lactobacillus.The cultural conditions of the Closlridium hutyricum strain CB2 were optimized through adopting the method of liquid stable submerged fermentation,including cultivation temperature,pH degree,and the main composition of the medium. The results showed that the adequate cultural conditions were:optimal medium,culture temprature being 36V. pi I degree being 7.0. culture period being 48h. under theconditions,cultivated for 48h,through counting the live the microbacteriums,the amount of CB2 was 12108cfu/ml,the rale of maturing gemma was 90%. To enlarged cultural scale within SOL fermentor,the result of 48h culture was showed that the amount of CB2 was 1.0 109cfu/ml,the rate of maturing gemma was 90%.Yeast y-11 and Lactic acid bacteria L-13 were incubated for 48h by mixed culture at 37C,and the percent of mixed inoculation was 1:4. The amount of y-11 was 0.2108cfu/ml,L-13 was 16.5 loVlu/ml.Based on studying cultivation of three strains and enlarging cultural scale,the technology of liquid fermentation of the multi-modulater of Closfridium hulyricum was optimized. The results showed that the process was simply practicable and low cost. It will be widely applied in animal husbandry.In preventive experiment,80 broilers were divided into two groups,test group broilers were feed with muti-modulater of Clostridium butyricum after ten days by Esherichia coli infection fighting,the result showed that prevention effective rate was 97.5%,the death rate of control group was 50%. In growth experiment,5000 broilers had been divided into two groups . One group was feed with multi-modulater of Closlridium bulyricum,while the other one was no used. The results showed that the test group had increased average weight gain,which was higher 8.28% than the control group,the feed-weight ratio was lower 5.77% than the control group.the death rate had discreased 65%. T-test showed that the difference between two groups were significant obvious(P<0.01). During the periods of experiment,the feces were selected at 14th day old and 35th day old,the results of detecting through counting the live microbacteriums showed that the multi-modulater had significant promotiveeffect on Bifidohaclerium and inhibitory effect on Esherichia coli in intestine tract. Inhibitory activity for bacteria in vitro showed that Laclobacilhis strain L-13 was able to produce a kind of antibacterial substance,which could inhibit the growth of E. coli.Because the cultivation of CB2was no strickly anaerobic circumstance,not only the technology of the multi-modulater was simple practicable and low cost,it was possible for widely produced,but also the multi-modulater being first applied to animal husbandry,which was a trend and road in developing green animal husbandry. |
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