TABLE 6.

Intestinal lesion scores of birds immunized with three injections intramuscularly and then infected with a mild-moderate or a severe challenge with C. perfringens

Group and proteinNo. of chickensNo. of chickens with the following lesion scores:Mean no. of chickens
01+2+3+4+5+
Chickens infected with mild-moderate challenge
    Vehicle-only controls100520122.3
    FBAa134611011.23
Chickens infected with severe challenge
    Vehicle-only controls110323122.72
    Alpha-toxinb100244002.2
    FBA141490001.57
  • a The immunized group had significantly fewer chickens with lesions than the unimmunized vehicle-only control group (Fisher's exact test, P ≤ 0.05).

  • b The birds in this group received three injections of alpha-toxin, in which the first and the third injections were with 20 μg and the second was reduced to 10 μg.