Studies On The Safety Test Of UV-Attenuated Eimeria Tenella YL Strain Vaccine And Its Humoral Immune Level After Mixture With Adjuvants

Coccidiosis is one of the important diseases of poultry. Currently chemical control is the main method for controlling coccidiosis and good results have been achieved. At the same time, the problems of coccidial drug resistance and drug residues appear. So vaccine researches make the wide concern, especially the research of the attenuated vaccine. The UV-attenuated Eimeria tenella YL strain vaccine were made. On this basis, these studies were carried out and the results were as followings:(1) The chicks were vaccinated with UV-attenuated E. tenella YL strain vaccine and adding adjuvant APS vaccine. The sera were prepared from different ages of chicken. And indirect ELISA was used to test the IgG titers in the sera. The results show that the chickens in the groups vaccinated with E. tenella YL strain vaccine had a high level of the seral antibodies. The IgG level in chickens was higher in APS vaccine group than that in only vaccine group. The highest IgG level was achieved by the vaccine mixed with 10% of APS.(2) The chicks were vaccinated with UV-attenuated E. tenella YL strain vaccine plus different concentrstion of APS. The clinical symptoms, bloody stools, OPG, lesion score and ACI were used to evaluate the anticoccidial effects of the vaccine in different ages of chickens. The results showed that the average weight gains in 10% APS vaccine group were not significantly different (P>0.05) compared with negative control group; but the differences were significant (P<0.01) compared with positive control group, or (P<0.05) compared with the vaccine group not plus APS. The clinical indicators in chicks of 10% APS vaccine group were less than that in only vaccine groups. Every vaccine group all had good anticoccidial effects. Among that the anticoccidial index in the second group was highest, up to 188.44.(3) A single dose vaccination, single dose repeated vaccination and a super-dose vaccination with the UV-attenuated Eimeria tenella YL strain vaccine used to assess the safty of the vaccine. Results show that the chicks in infected group did not show obvious clinical symptoms, the infection had low mortality, light cecum lesion and low OPG, and it had no obvious effect on the relative weight gain.(4) The average weight gains among the UV-attenuated E. tenella YL strain vaccine group, drug provention group (diclazuril) and drug treatment group (sulfachlorpyridazine) were tesed. Results showed no significant differences (P>0.05)were found. The relative weight gain was highest in the fourth group, up to 95.57 percent.