Microstructure of replacement chickens’ spleen after immunostimulant application

The article presents the histological studies of replacement chickens’ spleen. The predominance of medium lymphocytes over small ones in the periarterial area was noted after vaccination with “Raspol” being an immunostimulant against chicken infectious bronchitis. In the periarterial area, the predominance of medium lymphocytes over small ones was noted. The lumen profiles of the central, trabecular arteries were well defined, and there were no signs of connective tissue disorganization in their walls. The marginal part of the lymph nodules also remained well defined especially from the inner border and consisted of a large number of small lymphocytes and fewer medium ones. However, its width decreased markedly compared to the previous period of the organ examination. The indicated changes denote the signs of lymphoid cell hyperplasia in the lymph nodes, with a weak severity or absence of the consequences of the vaccine reactogenic effect on the connective tissue of the organ. In the birds receiving Fosprenil during immunization, the stimulation of lymphoproliferative activity continued during the first two weeks after vaccination and by the end of the one-month period it was not detected. However, signs of moderate postvaccination disorganization of the connective tissue components were observed at all follow-up periods. 28 days after vaccination, lymphoproliferative processes weakened markedly and signs accompanied by moderate disorganization of the components in connective tissue persisted in the spleen of the control group of birds