Prevention And Treatment Of Chaihuang Granules On Avian Infectious Bronchitis

Infectious bronchitis is an acute highly contagious respiratory disease in chickens causedby the infectious bronchitis virus. It could inhibit the growth and increase the motality andeliminating rates of chickens, thus causing great economic losses to the poultry industry.Therefore, it is significant for developing effective prevention and cure drugs. This study wascarried out to evaluate the prevention and treatment effect of chaihuang granules (CG) onavian infectious bronchitis by artificial infection and probe into its mechanism of action, andprovide a scientific basis for further research and development of new drugs and clinicalapplications. The results were as follows:(1)The making method of avian infectious bronchitis model: IBV-M41waspropagated five generations with specific pathogen-free (SPF) chicken embryos, then the IBdisease model was established though infecting15-day-old Hy-Line Brown chickens (0.4mL)by intratracheal injection IBV-M41and combining with low temperature, wet, congestion andother environmental factors. The mobidity rate of chickens were between70%and80%.Finally, through the observation of clinical symptoms, pathological autopsy and molecularbiology examination, it was proved that the chickens were infected by avain infectiousbronchitis virus.(2)Prevention and treatment effect of CG on avian infectious bronchitis:40015-day-old Hy-Line Brown chickens were randomly divided into8groups: CG preventiongroup (2.00g/L), CG treatment groups at low, medium and high doses treatment group(thedoses were3.00,4.00,5.00g/L respectively), Chinese and westernme dicine control group,model control group and the healthy control group. The chicken were challenged with theavian infectious bronchitis virus (IBV) M41except the healthy control group..Before7daysof challenging IBV, the CG was added into drinking water for preventing in prevention group,After48hours, the chickens in treatment groups were treated with drugs respectively until theclinical symptoms had disappeared. The results showed that the morbidity rate in theprevention group (2g/L) was reduced up to50%, and the difference was significantly lowerthan that in the model group (P <0.05). The mortality rate in CG treatment group at dose of4g/L was5.4%, and extremely significantly lower than that in the model group (P <0.01); Itscure rate (91.9%) was significant higher than that in Chinese and western medicine control group (P<0.05).(3)Effects of Chaihuang particles on serum antibody and serum biochemicalparameters: At the age of14,21,24and28, blood samples per chick in each group werecollected from heart, then the serum was separated, the serum antibody titers were determinedby avian infectious bronchitis antibody detection kit,serum protein、serum bilirubin and serumenzyme were assayed by Total Protein and Albumin Kit、Total Bilirubin and direct BilirubinKit、Alanine Aminotransferase and Aspartate Aminotransferase Kit respectively. The resultsshowed that the serum antibodies of chickens in each group have increased after infection,CG prevention group and each treatment group is the most significant. At the age of28, theantibody titer in treatment group with CG at dose of4g/L reached2805.0±486.1, and wasextremely significantly higher than that in other groups (P<0.01). In CG prevention group, theconcentration of serum globulin was maintained a higher level, and the concentration wassignificantly higher than that in healthy control group (P <0.05). The concentrations ofaspartate aminotransferase, direct bilirubin and indirect bilirubin in CG prevention andmedium dose groups decreased to normal levels, there were no significant differencescompared with the healthy control group (P>0.05). It indicated that CG had a protective effectfor the hepatobiliary system of chickens, and could improve the immunity, disease resistanceand adaptability by increasing the serum antibody titers and globulin levels in chickens. Inaddition, CG could also relieve the respiratory symptoms such as cough, sneeze and difficultybreathing caused by avian infectious bronchitis, and increase the weight of chickens.