| dc.description | Infectious bursal disease (IBD) or Gumboro disease is an acute, highly
contagious viral disease of young chickens characterized mainly by severe
lesions in the bursa of Fabricius (BF) followed by immunosuppression
(Cheville, 1967; Allan et al., 1972; Hirai et al., 1974; Fadley al. 1976;
Rosenberger and Gelb, 1978; Saif, 1994; Lukert and Saif, 1997). Infectious
bursal disease virus (IBDV), the oetiological agent of Gumboro disease,
belonging to the genus Birnavirus (Murphy et al. 1995), sub-genus
Avibirnavirus (Pringle, 1998), family Birnaviridae (Dobos et al., 1979; Brown,
1986), has been widely studied mainly for two reasons:
Firstly, the highly contagious virus can cause severe economic losses in
poultry industries due to high morbidity and mortality as a consequence of
B cell-dependent immunodeficiency (Muller et al., 1992; Lasher and Shane,
1994; Lukert and Saif, 1997; Nagarajan and Kibenge, 1997; van den Berg, 2000). | en_US |
| dc.description.abstract | A modified form of intermediate plus of infectious bursal disease virus vaccine
(CEVAC® IBD L) prepared from the “Winterfield 2512 G-61 strain” of infectious
bursal disease virus was tested for it’s pathogenicity in commercial chickens. A total
of 500 unvaccinated Cobb-500 commercial chicks, raised in relative isolation from
day old were used. 21 chicks were collected from experimental farm at day Du, Dis,
Dis, Diz, Doo Dz and Dz, respectively. 3 chicks were collected randomly from
experimental flock each respective day. Vaccine was administered at ocular route at
Du and Di with drinking water. All the sampled birds were subjected to detailed
necropsy. The visible gross morbid lesions, bursa-body weight ratios were recorded.
The bursae were collected, preserved at 10% formalin, processed, sectioned and
stained with Hematoxylin & Eosin for histopathology including determination of
bursal lesions scores. Data were analyzed statistically. One typically affected flock
was included in this study for the comparison.
The visible gross morbid lesion was not observed during necropsy and bursa-body
weight ratios were 2.75+0.60, 2.7140.39, 2.44+0.42, 3.39+0.13, 2.5840.55, and 2.15+0.16,
2.41+0.28 at Du, Dis, Dis, Diz, Dan Das, and D2, respectively. Histopathological lesions
were characterized as normal to severe lymphoid depletion with varying degrees of
follicular atrophy in the vaccinated flock of study work. The bursal lesions scored
were 0.67+0.33, 0.67+0.33, 2.00+0.58, 0.6740.33, 1.0£0.00, and 0.6740.33, 0.3340.33 at
Dn, Du, Dis, Diz, Doo Das, and Dz, respectively. No outbreaks were noted in the
vaccinated flock, but significant changes were found in the affected flock. | en_US |
