Prevention And Treatment Experimentation Of Self-made Chinese Herbal Compound In Chicken IBV-M41Challenged

Infectious bronchitis(IB) is an acute, highly contagious respiratory disease caused byinfectious bronchitis virus(IBV), whose is one of the foremost causes of economy loss withinthe poultry industry, affecting the performance of both meat-type and egg-laying birds. It isconsidered primarily a disease of the respiratory system such as gasping, coughing, trachealtales and nasal discharge while IBV-M41can cause kidney damage, a decline in eggproduction, and later a deterioration in shell and internal quality. Now the main method of IBprevention is vaccination, as a result of the wildly and highly using of IB vaccine, thevirulence and antigenicity of IBV has changed and led to the IB vaccine can’t reach idealeffect and even induce this disease. So it is significant to find a new kind of medicine toprevent and treat Infectious bronchitis.In order to improve the curative effect on infectious bronchitis in chickens, we designeda Chinese herbal medicine according to the pathogenesis. This prescription mainly consists ofRadix Isatidis, Folium Isatidis, Radix Scutellariae Baicalensis, Fructus Forsythiae Suspensae,Herba Houttyniae Cordatae, Radix Lithospermi, Herba Patriniae Scabiosaefoliae, RadixGlycyrrhizae et al. In order to investigate its effect, testing MTD of the Chinese herbalmedicine and ELD50of IBV-M41on embryo. In vivo tests, observing the clinic symptoms andpathological change, effect of Chinese herbal medicine on immune system and examination ofliver and kidney function. In vitro testing, add Chinese herbal medicine to tracheal ringcultures inoculated with IBV-M41so that find out the depressant effect of Chinese herbalmedicine to IBV-M41.The results was tested that MTD was1g/mL and ELD50was10-6.3/0.1mL. In vivo tests,the protection rate of the Chinese herbal medicine was100%and the recovery rate was noless than90%which indicated that the protective effect was better than its therapeuticeffecrtion. And the groups with Chinese herbal medicine in different dose had a significantpromotive effect on immune organ such as cloacal bursa and spleen, and as well as variouscytokines such as IFN、TNF and IgG. Besides these, this medicine can apparently protect liverand kidney from IBV compared with positive group. In vitro testing, the Chinese hebalmedicine worked on tracheal ring cultures inoculated with IBV had an high depressant effecton IBV and the protection rate was higher than80%, which was related to the content of the medicine.These dates indicated that the Chinese herbal medicine has favorable preventive andcurative effect on infectious bronchitis in chickens and marked antiviral effect. Andfurthermore the medicine is suitable used in preventive experiment much better than used incurative trail.