EN
In sheep raised in chamber system and fed concentrate fodder containing high dose of zearalenone and its metabolite (α- zearalenol), the clinical course of zearalenonosis was diagnosed. Control animals were kept on grazing-land from the spring to the late autumn, and only in winter time they were fed shredded wheat with the lowest concentration of zearalenone. These sheep showed no clinical symptoms of the mycotoxicosis. Zearalenone and α-zearalenol cause immunosuppression, which means that lymphocyte T CD4+ and lymphocyte T CD8+ percentages decline and CD4/CD8 ratio increases when compared with control animals. Zearalenone mycotoxin suppression effect modulates cellular immunological response, which is essential in suppression of post-vaccination immunity and infectious diseases development despite applying normal specific immunoprophylaxis.