Examination of Ornithobacterium rhinotracheale presence and pathomorphological changes in broiler respiratory organs in intensive broiler production

Abstract

Three flocks of broilers from the epizootiological region of South Banat, Serbia were chosen for examination, one flock with manifestation of respiratory disorders and two control flocks without respiratory disorders. In the flock with manifested respiratory disorders which was marked as flock number one (flock 1), high seroprevalence of specific antibodies for O. rhinotracheale (46%) was found in 30-dayold broiler chickens. The symptoms presented were: depression, reduction in feed consumption and water intake, sneezing, mucosal nasal discharge and facial edema. Production results were below technological standards due to increased mortality, decreased growth range and increased number of stunted chickens. Autopsy found frequent changes in the trachea, air sacs and lungs, which were manifested as: tracheitis catarrhalis, aerosacculitis fibrinosa and pneumonia fibrinosa. In control flocks marked as flock number two (flock 2) and flock number three (flock 3) where 4 % and 8 % of seropositive chickens were found, there were no clinical signs which would indicate illness, and production results were much closer to technological standards as compared with flock 1. Autopsy found lower number of chickens with changed respiratory organs as compared with flock 1; in addition intensity of changes was lower than in flock 1. No case of airsacculitis was found in flocks 2 and 3, which was a frequent finding in flock 1.