| The purpose of this experiment is to study the effects of substituting antibiotics with Chinese herbal extracts as feed additives. The effective components of Chinese herbs were extracted and condensed by physical and chemical methods.The efficacy of this kind feed additives were verified by in vitro bacteria inhibiting test and animal feeding trial.This study include four parts as follows: herbal medicines culling and extracting of effective component, herbal formulation, measuring of effective component and feeding trial verification. 1 .The extracting process of Chinese herbsAccording to different chemical characteristics of the effective components in Chinese herbs, extracting process were designed and divided into two methods: refined and simple extracting process.The refined extract processing were determined the optimal abstracting techniques by in vitro bacteria inhibiting test.In screened medicines,Scutellaria and Cortex Fraxini show the best antibiotic efficacy whose inhibitory diameter, to Coliform and Salmonella,were 13.46 L17,13.47 1.19,12.98 1.29,13.28 0.92 respectively.However,The bacteria inhibiting effect of others was weak. The extracts of Houttuynia cordata Thunb, by simple extracting process ,was no bacteria inhibiting activity. 2.The determing of optimal formulation experiment by orthogonal testFour kinds Chinese herbs,Scutellaria, Cortex Fraxini, Pulsutilla and Portulaca oloracea, which have good bacteria inhibiting efficacy have been screened by the lowest bacteria inhibiting concentration of medicine experiment. The experiment was designed according to four factors and three levels orthogonal table. The result shows that A1B1C3D3 and A1B1C3D2 formulation have efficient efficacy.The further study verified the A1B1C3D3 formulation as the result of orthogonal test and called formulation I .In addition, Scutellaria and Cortex Fraxini were selected to design formulation II whose ratio was7:3. To release the diarrhea symptom of piglets,the 10% Aucklandia was added to formulation I and II and called refined formulation I#and2# respectively. 3.Determining of the effective compinents in additivesTo determine the quality of products and lay down corresponding standard, the experiments have determined the principal component,Bacicalin,of the products. The ultraviolet absorption spectrophotometer was applied and detective wavelength was 276nm.The determined Bacicalin content in refined formulation l#and 2# were 1.75 0.11,6.85 0.72 respectively.Through the stability experiment and adding samplerecovery ratio experiment,the method that used to determine the Bacicalin content is convenient and trustful.4.Effect of Chinese herb extracts on the growing characteristics and blood bio-chemical index in pigletsIn 0-15d,16-25d treated groups,the ratio of diarrhea difference was not remarkable(P>00.5),but the diarrhea ratio in refined formulation 2# group was remarkably lower than that of other groups(P<0.05)during the whole experiment period.Comparing with the control group,the diarrhea ratio in refined formulation l*group decreased by 5.5%,but the difference was not remarkable.Comparing with the control andLinco-spectin group,the daily weight gain of the refined formulation 1# group increased remarkably (P<0.05) by 29%,25% and 17%,25% respectively during the first experiment period(0-15d) and the whole experiment period. Likewise ,the daily weight gain of refined formulation 2# group also increased by 17%,25% and 20%,26%(P<0.05).But comparing with Linco-spectin group,the food to weight ratio difference was not remarkable.The extracts of Chinese herbs can remarkably increase the activity of ALT(P<0.05) in serum. Comparing with the control and Linco-spectin group,the ALT activity of refined formulation 2# group increased by 22.36% and 13.09% (P<0.05)respectively.The ALT activity of refined formulation 1# can also increase, but the difference is not remarkable(P>0.05).The addition of Chinese herbs can remarkably increase the content of total protein(TP) in serum(P>0.05). Comparing with the... |
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