Chronic toxicity of fumonisins in turkeys.

Fumonisins are mycotoxins that are found worldwide. They are mainly produced by Fusarium verticillioides during its development on corn. The main toxic effects of these molecules have been well characterized in poultry in the case of acute exposure, but the subclinical and economic effects of chronic exposure are less known. Whereas the latest European recommendations suggest that maximal levels of fumonisins in corn could reach 60 mg/kg and the maximal contamination of poultry feeds could reach 20 mg/kg, no study is available at this level in turkeys. The aim of the present work was thus to characterize the effects of exposure to fumonisins (concentrations of 0, 5, 10, and 20 mg of fumonisin B1 + fumonisin B2/kg of feed) on feed consumption and growth in turkeys over a period of 9 wk. Main biochemical parameters of the liver and alteration of sphingolipid metabolism were investigated in plasma, liver, and kidney. The main results showed no effect on feed consumption and growth in exposed turkeys. Moreover, no effect was observed on the weight of tissues and markers of liver injury. By contrast, a disruption of sphingolipid metabolism was clear at a level of exposure of 10 and 20 mg of fumonisin B1 + fumonisin B2 mg/kg of feed. Both hepatic and kidney concentrations of sphinganine increased gradually throughout the exposure period. These results reveal that disruption of sphingolipid metabolism is an early and sensitive biomarker of fumonisins exposure in turkeys; the consequences on these alterations remain to be established.