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 protein | No. of chickens | No. of chickens with the following lesion scores:
|
Mean no. of chickens | |||||
|---|---|---|---|---|---|---|---|---|
| 0 | 1+ | 2+ | 3+ | 4+ | 5+ | |||
| Chickens infected with mild-moderate challenge | ||||||||
| Vehicle-only controls | 10 | 0 | 5 | 2 | 0 | 1 | 2 | 2.3 |
| FBAa | 13 | 4 | 6 | 1 | 1 | 0 | 1 | 1.23 |
| Chickens infected with severe challenge | ||||||||
| Vehicle-only controls | 11 | 0 | 3 | 2 | 3 | 1 | 2 | 2.72 |
| Alpha-toxinb | 10 | 0 | 2 | 4 | 4 | 0 | 0 | 2.2 |
| FBA | 14 | 1 | 4 | 9 | 0 | 0 | 0 | 1.57 |
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.