Group | Number of chickens per group | Air sac lesion observed | Number of death | Percentage |
A (control) | 20 | 18 | 2 | 90 |
B (live MG vaccinated) | 20 | 0 | 0 | 0 |
C (Vaccinated with trial bacterin, MG) | 20 | 0 | 0 | 0 |