On the effects of a hydrothermal treatment of deoxynivalenol (DON)-contaminated wheat in the presence of sodium metabisulphite (Na2S2O5) on DON reduction and on piglet performance

Several studies were undertaken to examine the effects of a hydrothermal treatment of deoxynivalenol (DON)-contaminated wheat in the presence of sodium metabisulphite (Na2S2O5) on DON reduction using a laboratory conditioner. Treatment of a wheat batch containing 7.6 mg DON per kg with 10 g Na2S2O5 per kg for 15 min at 100 °C, at a moisture content of 22%, and a permanently saturated steam supply under permanent mixing, was sufficient to reduce the DON-concentration to 0.28 mg/kg. The success of this treatment was confirmed in a piglet experiment (three weeks, initial average live weight 12.3 kg) where the hydrothermal treatment of the DON-contaminated wheat (400 g wheat/kg diet) improved performance parameters to a greater extent as compared to the uncontaminated control wheat. Overall daily live weight gain was 0.51, 0.56, 0.43 and 0.54 kg/d for piglets fed the uncontaminated wheat, the uncontaminated and treated wheat, the DON-contaminated wheat and the treated DON-contaminated wheat, respectively (p < 0.05). The corresponding feed to gain ratios were 1.79, 1.58, 1.76 and 1.68 kg/kg, respectively (p < 0.05). Moreover, DON-concentrations in serum of the piglets clearly reflected the analyzed DON-concentrations in the diets. DON-concentrations of the diets were 0.2, < 0.03, 3.2 and 0.1 mg/kg, respectively, and DON-concentrations in serum were <5, <5, 15.5 and <5 ng/mL, respectively. ition, Na2S2O5-treatment of wheat reduced the in vitro toxicity of DON-contaminated wheat and did not affect toxicity of the control wheat according to the MTT(methylthiazoltetrazolium)-test. The IC50 (IC50: inhibitory concentration 50%—the lowest substance concentration which reduces the absorption in the MTT-assay on 50% of the control values) concentrations were 400, 400, 50 and 400 mg/mL of crude extract for untreated control wheat, for treated control wheat, for untreated DON-contaminated wheat and for treated DON-contaminated wheat, respectively. concluded that Na2S2O5-treatment at 10 g/kg wheat at a DON-concentration of 8 mg/kg is an effective tool to overcome the depressing effects of DON on feed-intake in piglets.