Abstract:

In order to verify the effect of Baihu Dingchuan oral liquid of new veterinary drugs,the effects of infectious bronchitis virus (IBV) on the proliferation inhibition test, tracheal cilia movement test and SPF chickens infected with IBV were tested.The test solution was mixed with an equal amount of IBV solution,inoculation of 11-day-old SPF chicken embryo,incubation at 37℃ for 168 h.RT-PCR was performed to detect IBV in kidney of live chick embryo.The results showed that the survival rate of 168 h chicken embryo was 80% in the drug group,but the positive control group was 20%, and there was significant difference between two groups (P<0.05). In the test drug group, no band was detected by RT-PCR, but the target band appeared in the positive control group.After 40 days old SPF chickens were administered continuously for 3 days, 0.02 mL of ink was injected into the trachea. The distance of ink movement in 1 min was measured. The results showed that the migration distance of ink was extremely significantly higher than that of saline control group (P<0.01).In the 17-day-old SPF chickens, IBV-M41 was infused into the nasal mucosa with 0.3 mL. After 24 h, 1 mL/kg was administered for 5 days. The results showed that there were significant differences in clinical symptom score and cure rate between the test drug group and the control group (P<0.05). There was no significant pathological changes in the tracheal mucosa of the experimental group, but the pathological changes in the positive control group were significant. The above results showed that Baihu Dingchuan oral liquid had good inhibitory effect on IBV in vitro, which could promote the movement of tracheal cilia, and had good clinical control effect on infectious bronchitis.

Key words: Baihu Dingchuan oral liquid; infectious bronchitis; tracheal cilia exercise test; artificial infection test