Fusarium mycotoxicoses in poultry and swine: A comparative study of characterization and prevention

Deoxynivalenol (DON, vomitoxin), zearalenone and fusaric acid are the most commonly found Fusarium mycotoxins in Ontario-grown feedstuffs. Trials were conducted to compare the effects of feeding diets naturally-contaminated with Fusarium mycotoxins on broiler chickens and starter pigs. The contaminated diets were formulated by replacing corn and wheat of the control diet with those naturally-contaminated with Fusarium mycotoxins. A polymeric glucomannan mycotoxin adsorbent (GM polymer) was also tested for its ability to prevent Fusarium mycotoxicoses. Starter pigs were fed approximately half the amount of contaminated grains compared to broiler chickens. Feed intake and weight gain in pigs fed contaminated grains was reduced by 32 and 34%, respectively, while the decreases in broiler chickens were 15 and 12%. There is strong evidence that serotonergic and α2-noradrenergic systems interact antagonistically through medial hypothalamic satiety mechanisms. Serotonergic neurotransmitter concentrations were elevated, while norepinephrine concentrations decreased in the brain of pigs fed contaminated grains. The lack of an antagonistic interaction of these two systems on feed intake might explain feed refusal in pigs. In contrast, both norepinephrine and serotonergic neurotransmitter concentrations were elevated in broiler chickens, thus permitting the possible antagonistic interaction between the two systems. This situation may explain the less severe feed refusal seen in broiler chickens. The feeding of contaminated grains increased serum IgA and IgM concentrations in pigs, but not in broiler chickens. Peripheral blood monocyte and B cell numbers were decreased in chickens fed contaminated grains but not in pigs. The feeding of contaminated diets did not significantly alter contact hypersensitivity and antibody response. It was concluded that the changes in the number of peripheral blood immune cells were more prominent in broiler chickens than in starter pigs, but this was not enough to alter antibody and cell-mediated immune responses. Glucomannan polymer was able to prevent some of the adverse effects of Fusarium mycotoxins on serum immunoglobulin concentrations, brain regional neurotransmitter concentrations, serum chemistry and hematology. It was, however, unable to prevent Fusarium mycotoxin-induced reduction in feed intake and weight gains at the levels of inclusion of contaminated grains in the current studies.