The Histological Changes in Bursa of Fabricius on Chickens Vaccinated with Intermediate and Hot Strains of Vaccines against Gambaro Disease.

Abstract. The study material represent histological modifications in bursa of Fabricius on vaccinated chickens with intermediary and hot vaccines strains.Was established that intermediary vaccine strains against infectious bursitis make the changes in bursa tissue which is observed at 10, 20 and 30 days after vaccination and expressed with hypertrophy of lymphoid follicles, partial destruction of lymphocytes, plasma cells, accumulation of serous or sero-bloody exudates in the interfollicles space and return to normal structure over 30, 40 days after vaccination. Hot vaccines strains causing a deep tissue destructive processes that are expressed with cover epithelium detachment, mass destruction of lymphoid follicle lymphocytes, and accumulation of sero- sangvinolen exudates in interfollicles and follicles regions. Hot vaccine strains caused destructive lesions in tissue of bursa of Fabricius leading to further immunosuppressant state and low post vaccination response against anther infectious diseases