©ПАТОМОРФОЛОГІЧНІ ЗМІНИ У ЛІМФОЇДНІЙ ТКАНИНІ БУРСИ ФАБРІЦІУСА КУРЕЙ, ВИКЛИКАНІ РІЗНИМИ ВАКЦИННИМИ ТА ПОЛЬОВИМИ ШТАМАМИ ВІРУСУ ХВОРОБИ ГАМБОРО ВИЯВЛЕНИМИ В УКРАЇНІ

Abstract

The infectious bursal disease virus was detected in the Gumboro рrovince of the United States in 1962 and since then has become widespread throughout the world. Gumboro disease is characterized by severe immunosuppression in affected birds, and often mortality. Since 1986, very virulent strains of IBDV appeared in central Europe, and caused up to 70% mortality of chickens. Vaccination became the main method of protection against the disease. It is important to differentiate the post-infectious and post-vaccination effects of the virus on the bursa of the Fabricius of birds to control the vaccination process. Therefore, the aim of the study was to detect the effects of various vaccine and very virulent IBDV strains on the bursa of Fabricius of chickens. For this purpose, histological examination of bursas of vaccinated and infected birds was carried out. Samples were taken from different poultry farms in Ukraine. In results of the study we observed positive correlation between degree of depletion of the cloacal bursa and the residual virulence of the vaccine strains. Also, we detected very severe (up to 100%) depletion of bursa follicles caused by very virulent strains. The results of the work can be further used for the analysis of the post-vaccination reaction in chickens during preventive measures in places of industrial bird production.