Individual and combined effects of subclinical dosesof deoxynivalenol and fumonisins in piglets

Scope: Deoxynivalenol (DON) and fumonisins (FB) are the most frequently encounteredmycotoxins produced by Fusarium species and most commonly co-occur in animal diets.These mycotoxins were studied for their toxicity in piglets on several parameters includingplasma biochemistry, organ histopathology and immune response.Methods and results: Twenty-four 5-wk-old animals were randomly assigned to four differentgroups, receiving separate diets for 5 wk, a control diet, a diet contaminated with either DON(3 mg/kg) or FB (6 mg/kg) or both toxins. At days 4 and 16 of the trial, the animals weresubcutaneously immunized with ovalbumin to assess their specific immune response. Thedifferent diets did not affect animal performance and had minimal effect on hematologicaland biochemical blood parameters. By contrast, DON and FB induced histopathologicallesions in the liver, the lungs and the kidneys of exposed animals. The liver was significantlymore affected when the two mycotoxins were present simultaneously. The contaminateddiets also altered the specific immune response upon vaccination as measured by reducedanti-ovalbumin IgG level in the plasma and reduced lymphocyte proliferation upon antigenicstimulation. Because cytokines play a key role in immunity, the expression levels of IL-8, IL-1b, IL-6 and macrophage inflammatory protein-1b were measured by RT-PCR at the end ofthe experiment. The expression of these four cytokines was significantly decreased in thespleen of piglets exposed to multi-contaminated diet.Conclusion: Taken together, our data indicate that ingestion of multi-contaminated dietinduces greater histopathological lesions and higher immune suppression than ingestion ofmono-contaminated diets.