STUDIES ON THE PROFILE AND RELATIONSHIP OF MATERNAL AND VACCINAL ANTIBODIES IN THE PREVENTION OF INFECTIOUS BURSAL DISEASE IN CHICKENS
STUDIES ON THE PROFILE AND RELATIONSHIP OF MATERNAL AND VACCINAL ANTIBODIES IN THE PREVENTION OF INFECTIOUS BURSAL DISEASE IN CHICKENS
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Date
1985-11
Authors
ABDU, PAUL AYUBA
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Abstract
The presence of infectious bursal disease virus
maternal antibody in broiler chicks was checked
every other day from day-old for 29 days and its
decay pattern determined. Maternal antibody was
found in the chicks sampled and its decay pattern
linear. It was present in all the chicks sampled
at day-old but absent in all the chicks sampled at
19 days old. These findings suggest that
vaccinating these chicks against infectious bursal
disease at day-old would be ineffective since
maternal antibody has been shown to interfere with
vaccination and that if these chicks were exposed
to infectious bursal disease virus at day-old they
would be protected. On the other hand, all the
chicks would be expected to be susceptible at 19
days old.
Different sets of chicks similar to those used
above were each vaccinated with infectious bursal
disease vaccine at weekly intervals from day-old for
29 days. The presence of active infectious bursal
disease virus antibody was determined at three,
seven, 14 and 35 days post-vaccination. It was
detected at 35 days post-vaccination in chicks vaccinated at one, eight or 15 days old and at 14
and seven days post-vaccination in chicks vaccinated
at 22 or 29 days old respectively. The prompt
immune antibody response observed in chicks
vaccinated at 22 or 29 days old than in. chicks
vaccinated at one, eight or 15 days old was possibly
due to the absence of maternal antibody in the chicks
vaccinated at 22 or 29 days old since maternal
antibody level decreases with age and is usually
absent by the time a chick is three or four weeks
old.
Chicks similar to those used in the vaccination
trials above were challenged with a virulent field
infectious bursal disease virus at weekly intervals
from day-old for 29 days. Chicks challenged at eight,
15, 22 or 29 days old were susceptible based on bursal
atrophy, bursal lesions and presence of infectious
bursal disease virus precipitin antigen in the bursa
of Fabricius. However, only 40 and 90% of the chicks
challenged, at eight or 15 days old respectively were
susceptible while all the chicks challenged at 22 or
29 days old were susceptible. Only the chicks
challenged at 29 days old showed clinical signs.
The results suggest that the initial level of
maternal antibody at day-old in the chicks challenged at 22 or 29 days old was not high enough to have
lasted 22 or 29 days and that chicks as young
as eight days old could be infected with infectious
bursal disea virus without showing clinical signs.
In the field this is possible because infectious
bursal disease is enzootic in Nigeria. Chicks
exposed this early may be permanently immune-suppressed.
In conclusion, it is recommended that maternallyimmune
chicks be vaccinated against infectious bursal
disease at seven and 21 days of age and the chances
of exposure to field infectious bursal disease virus
be minimized by good management and hygienic
practices.
Description
A Thesis Submitted to Ahmadu Bello University,
Zaria in partial fulfillment for the degree
of MASTER Of SCIENCE (Avian Medicine)
Department of Veterinary Surgery
and Medicine, Ahmadu Bello University,
Zaria, Nigeria
Keywords
STUDIES,, PROFILE,, MATERNAL,, RELATIONSHIP,, PREVENTION,, CHICKENS,, DISEASE ,, INFECTIOUS,, BURSAL,