| Popis: |
Flock A, 8,400 7-week-old Silver Rocks, was vaccinated at 7 days by water method against Newcastle disease and infectious bronchitis. There was little reaction except a persistent sneeze, followed by exacerbation of respiratory signs 3 days prior to submission. This was clinically considered to be Newcastle disease. This situation continued for 10 days, during which time 150 birds died rather suddenly. Another group of 6,000 6-week-old birds was unaffected although they were on the same farm but in different buildings. Flock B, 12,500 7-week-old Vantress Crosses, was vaccinated at 10 days by water method against Newcastle disease and infectious bronchitis. At 5 weeks of age infectious laryngotracheitis (ILT) occurred; control was effected by eye vaccination of a "mild strain" of ILT virus. At the time of |
