C. perfringens vaccine was used for prevention of necrotic enteritis (NE) in male layer chickens in presence of predisposing factor. Vaccinated chicken groups subjected to predisposing factor showed improved results as compared with non vaccinated group. Three days average body weights of treated infected showing that birds of coccidia vaccine having the highest values from the 1st -7thdpi, followed by coccidia vaccine group with aflatoxin group, while infected non vaccinated group showed the lowest values.
Regarding weekly and cumulative body weight gain (BWG), feed intake (FI) and feed conversion rate (FCR) of chickens groups given NE vaccine and challenged with C. perfringens culture. Vaccinated groups were higher than infected control groups. Bursa and thymus lesions in vaccinated groups were milder than non vaccinated. C. perfringens vaccine resulted in lowering lesion score in both intestine and liver scores till the the 9thdpi as compared with nonvaccinated group. Pathological finding showed that there was a good correlation comparing between both gross and macroscopical finding especially in intestinal changes.
The role of NE vaccine in prevention of NE disease needs more investigations especially in presence of immunosuppressive factors. Single dose of NE vaccine had role in minimizing the effect of challenge with C. perfringens broth culture on performance, gross and histopathological lesions.The used NE vaccine had a role in prevention of NE in presence of aflatoxins and/or coccidia vaccines. This finding requires more investigations especially in presence of immunosuppressive factors.