Safety And Immune Effects Of A Live Attenuated Quadrivalent Coccidiosis Vaccine

Coccidiosis has been one of the most feared chicken disease. The annual economic losses of poultry industry in the world is estimated at about $ 3 billion because of higher morbidity(50~70%) and mortality(20~30%, sometime up to even 80%) of this disease. The disease has been largely controlled through the anti-coccidial drugs added directly into feed. However, coupled with another factor that the question of drug residue in poultry products is increasingly concerned, rapid appearance of resistant Eimeria strains and very few new drugs developed have stimulated studies on alternative control methods, one of which is vaccination with a live vaccine. Therefore, the present studies were carried out to evaluate the safety and immune effect of live vaceines against coccidiosis of chicken E. tenella, E. necatrix, E. maxima vaccine.(1) Safety Test: 3-day-old chicks were inoculated to 10-fold, 100-fold vaccine. The safety was determined by clinical symptoms, mortality, bloody stools, bowel disease and other aspects. The results showed that the control group, 10 times immunity group and 100 times immunity group had no death, the bloody and bowel disease are standard. This indicates that the vaccine is safe.(2) Effect Test: The immunity group chicks were vaccinated with the first immunization, the second immunization and the third immunization at 3 days old, 8 days old, 16 days old, respectively. The effectiveness was determined by clinical symptoms, mortality, bloody stools, bowel disease and other aspects after attack sporulated oocysts. The results showed that the mortality of the control group was 30% and the immunity group was 0%, and the immunity group was better than control group. This indicates that the vaccine is effective.