| Avian coccidiosis is an important disease that widely spreads with a high incidence in chicken farms and is often found in chicks at 15 to 50 days old. If not effectively controlled, the prevalence of infection will be high up to 50 %～70 % with a mortality of 20 %～30 % or 80 % in severe cases. Statistical analysis indicated that the annual cost caused by the disease is estimated at￡200 million in the world. Current control of coccidosis mainly depends on synthetic chemicals or antibiotics. The durable use of the chemical drugs in the poultry industry easily leads to the resistant strains as well as the drug residues in the chickens and their products which are harmful to humans. Therefore, more and more research has shifted to non-antibiotic approaches such as medicinal herbs.So far, study on monomer abstraction from Dichroa Febrifuga deeply, discovered that until now the alkaloid extraction process and the abstraction method study report are few about Dichroa Febrifuga. It is really micro studying on the common avian coccidiosis of livestock and fowl among the numerous pharmacologicalactions of alkaloid extraction from Dichroa Febrifuga. According to the above, this article study on each committed step for new veterinary medicine, including the alkaloid extraction, abstraction and the research of anticoccdidal activity in chicken, to provide some basic theory for a large-scale industry. The main results were indicated as follows:First, the content of febrifugine.The present work presents a colorimetric method based on the principle that o-aminobenzoic acid is produced by the alkaline hydrolysis of the quinazolone structure of the febrifugine molecule, which can be determined colorimetrically by coupling with N-1-naphthyl ethylene diamine after diazotization. The content of febrifugine determinated by UV spectrophotometer and is 0.327 %.Second, research on the technical of alkaloid extraction from Dichroa Febrifuga. Using the orthogonal experimental designed method, taken the evaluating target by the extracting weight and the content of febrifugine, analyzed by software SPSS 14.0, inspected extraction process of the ultrasonic wave method . The condition is the extraction temperature 50℃, the ratio of dosage liquor 1:5, extraction time 1 h.Third, in order to evaluate the security of dichrone, the acute toxicity of dichrone was tested in mice. After preliminary experiment to determine the dosage, 60 mice were selected and divided into 6 groups. After giving medicine lavage and observing for 7 days, the acute toxic reaction was recorded and the LD50 value and 95 % confidence limit of LD50 were determined by the modified Karber's method. The results showed that some mice appeared toxic reaction and death. No pathological change was found in the main organs by necropsy of dead mice. The LD50 was 18.16 g/kg and its 95% confidence limit was 15.35～21.49 g/kg. The results demonstrated that the dichrone has lower toxicity and safety for clinical application.Forth, in the experiments of prevention and treatment of chicken coccidiosis, we made chicken coccidiosis with Eimeria coccidia. We uesed different doses of the febrifugine to prevent and treatchicken coccidiosis, so we confirmed the best dose of clinical treatment and prevention of febrifugine. It is good therapeutic effect to treat chicken coccidian with 20 mg/kg of the febrifugine, and its anticoccidial index (ACI 166.31). |
