Comprehensive Prevention And Treatment Research Of DVH In Zibo City

Duck viral hepatitis(DVH) is an acute, high-touch and mortal infectious disease caused by DHV which usually lead to high mortality in infant ducks. It is believed the primary disease threatening to duckery. In order to prevent and control the disease in ZiBo city, a comprehensive DVH epidemiology study was carried on.In this dissertation, a comprehensive epidemic survey involving 6 districts/counties in ZiBo city was conducted and a whole duck viral hepatitis epidemic status was acquainted. Type I DVH was separated from duck hepatitis virus samples and used to synthesize successfully the yolk antibody which gained the titers of 28. Experiments show that the survival ratio of only one day old inoculated ducklings is up to 95.14%; while the overall therapy ratio of the diseased ducks is up to 94.67%. Consequently, a comprehensive prevention and therapy plan about DVH in ZiBo city is studied and proposed.This study was conducted through three distinct tests:Test One an epidemic investigation on duck virus hepatitis in ZiBo city Pathogenic status, clinical symptom, pathogenic mechanism and prevalence law was investigated on duck groups in 42 duckeries of 8 districts in ZiBo city. The result shows that the incidence of viral hepatitis disease accounted for 42.5 percent of all the ducks, being a top disease, which is the leading cause of ducklings'death. Of the investigated 218 duck disease cases, the incidence of a 3-day-old to 14-day-old was up to a total of 168 cases, accounting for 75%. In spring, incidence of this disease was most, amounting to 40%; while the number was up to 36% in winter. The incidence in large scale duckery accounted for 31%, up to 69; while in the free-range farms the number was 65%, up to 142. Through the investigation, the prevalence and clinical characterization was primarily acquired.Test Two separation and identification on duck hepatitis virusThe suspected DHV livers from died ducklings in Huantai, Gaoqing and Linzi district were selected as samples. And then they were respectively carried on chicken embryo neutralization test, chloroform-sensitive experiment, ELD50 determination and regression analysis, through virus separation, chicken embryo inoculation and virus purification. The result implied that distinct virus value were carried with 105.3,105.6 and 105.1 and death ratio of the ducklings is 75%,87.5% and 75%. Typical symptoms of viral hepatitis was also found in the test.Test Three the therapy efficiency of yolk antibody on Duck viral hepatitisUsing the attained bacterin, antibody was successfully prepared and its neutralization effect was up to 28. Then the prevention tests were conducted with the yolk antibody employed. It was shown that the protection ratio of only one day old inoculated ducklings is up to 95.14%; while the overall therapy ratio of the diseased ducks is up to 94.67%.