PATHOLOGICAL INVESTIGATION OF INFECTIOUS BURSAL DISEASE (IBD) IN SONALI CHICKEN AT CAIBANDHA DISTRICT

Abstract

The study was designed to investigate prevalence and pathology of Infectious Bursal Disease (IBD) of sonali chicken at different upazila in Gaibandha Distict in a short six month duration starting from Janury to June2014. Eight sonali chicken farms with sum of 3230 birds of various age group from four different upazila like Sadar, Palashbari, Sudduiapur and Gobindogonj were suspected for Infectious Bursal Disease (IBD). On the basis of detail about farm history, clinical signs and postmortem investigation of infected chicks, the prevalence of IBD was 10%, 10.95%, 7.89% and 12% in Sadar, Palashbari, Suddulapur and Gobindogonj upazila, respectively with an overall prevalence 10.21% at Gaibandha district. The prevalence of IBD in sonali chickens was the highest (11.98%) at 4" week of age and the lowest (7.88%) at 6" week of age. No sonali chick was identified as positive for IBD in their first two weeks of age. The highest mortality was observed at Gobindogonj upazila (5%) and the lowest (3.80%) at Palashbari upazila, with total mortality rate 4.19%. The necropsy findings of infected chicks revealed haemorrhages on thigh and brest muscles; enlarged, edematous, hyperemic and haemorrhagic Bursa of Fabricious followed by atrophy. In some cases kidneys were found swollen. Severe lymphoid depletion and reactive cells infiltration in the interfollicular space were found in histopathological studies by using H & E stain. Therefore, it was concluded that susceptibility of chicks to IBD is influenced by its age. Ruffled feather, depression, whitish diarrhoea with haemorrhagic muscles and inflammed, edematous, hyperemic Bursa of Fabricious is attributable to Infectious Bursal Disease (IBD).