Tunio M.T., Abro S.H. , Rind R., Wagan R., Hashmi H.A.
Abstract
Study was carried out to evaluate in-ovo vaccination against Infectious Bronchitis (IB) virus. Two hundred forty
specific pathogen-free (SPF) fertile chicken eggs of Babcock layer were selected and divided into groups A, B, C,
and D (i.e. 60 eggs were kept in each group). The embryonated eggs of group A, B and C were vaccinated with IBV M-41
strain using the manual micro-injection system at 18 days of incubation period while group D were kept as control.
After hatching, hatchability percentage, antibody titre in sera of vaccinated chicks was recorded. In-ovo vaccination
with different dilution affected the hatchability in embryos as compared to the chicks did not receive vaccine.
The chicks of group A received vaccine at the dose of 0.1ml with virus serial dilution 10-6 showed 83.33%
hatchability while group B received vaccine the dose of 0.1ml with virus serial dilution 10-5 yielded 68.33%
hatchability. The chicks of group C were vaccinated with the dose of 0.1ml dilution 10-4 had 63.33% hatchability,
Chicks of group D receiving no vaccine showed 96.66% hatchability. The blood of all the vaccinated birds was examined
for haemagglutination inhibition test at weekly interval and clear variation in the antibodies titre was evident.
The chicks received 0.1ml dilution 10_6 dose of vaccine had the maximum 5.75 antibody titre followed by 10-5
( 5.5titre) and 10-4 ( 4.75 titre) at the the end of 5th week. Antibody titre groups A, B and C was gradually
decreased to 5.00, 4.62 and 3.15, respectively upto the end of 7th week. No antibody titre was observed in chicks of
group D.
Key words:
Infectious Bronchitis Virus, hatchability, in-ovo vaccination, chicks, antibody titre chicken