Lymphocyte subpopulations in blood and duodenal epithelium of broilers fed diets contaminated with deoxynivalenol and zearalenone

The effects of two dietary levels of Fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZEA) on subpopulations of peripheral blood and duodenal intraepithelial lymphocytes in Ross 308 hybrid broiler chickens of both sexes were examined. From the day of hatching to the age of two weeks three groups of chickens were fed the same uncontaminated control diet. After 14 days, broilers in two of the groups were switched to otherwise identical experimental diets containing DON and ZEA. The diet of Group 2 contained DON and ZEA, each at a level of 3.4 mg/kg and the Group 3 diet contained DON and ZEA at 8.2 and 8.3 mg/kg, respectively. Contaminated diets were prepared in the laboratory using maize cultivated with Fusarium graminearum. Group 1 (control) continued with intake of uncontaminated diet for entire experiment. At the age of four weeks samples of blood and duodenal tissue were collected. Intake of both contaminated diets reduced blood phagocytic activity (P<0.001) whereas numbers of various types of peripheral white blood cells were not affected. Among different blood lymphocyte populations investigated, only the counts of CD3+ cells were lowered by diet with higher mycotoxin levels (P=0.021). In duodenal epithelium, the large increase in cells expressing MHC II was observed due to intake of both diets contaminated with lower and higher mycotoxins contents (P<0.001) while the IgA+ cell subpopulation was decreased (P=0.018). The other intraepithelial lymphocyte subpopulations in duodenum examined (CD3+, CD4+, CD8+ and CD44+) were not influenced by intake of contaminated diets (P>0.05). Results suggest that intake of diets contaminated with DON and ZEA at medium levels may affect some blood and intraepithelial duodenal lymphocyte subpopulations and compromise blood phagocytic activity in broilers.