Serological biomarkers of zearalenone exposure in beef heifers receiving anti-mycotoxin additive

Abstract

The inclusion of anti-mycotoxin additives (AMA) in the diet of production animals has been widely used to avoid mycotoxin exposure. In order to confirm the efficacy of such products in vivo, measurement of mycotoxins and/or their metabolites in biological fluids is preconized. This study aimed at determining the serological biomarkers of zearalenone (ZEN), α-zearalenol, β-zearalenol, α-zearalanol, β-zearalanol (β-ZAL) and zearalanone, to evaluate the efficacy of an AMA in beef heifers. The trial lasted 37 days: 11 days of adaptation, 21 days of actual experiment, and 5 days of regression. Twenty-four heifers were randomly assigned to receive one of the following treatments (n=6/group): (T1) basal diet (control); (T2) basal diet + 5 mg/kg of ZEN; (T3) basal diet + 5 mg/kg of ZEN + 2.5 kg/t of AMA; and (T4) basal diet + 5 mg/kg of ZEN + 5.0 kg/t of AMA. Blood sampling was performed on different days after the diet was given. The samples were centrifuged to obtain the blood serum, and then analysed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). β-ZAL was detected above the limit of quantification both in the unconjugated (>0.60 ng/ml) and conjugated (>0.90 ng/ml) forms. The remaining metabolites presented concentrations under the limit of detection. In the efficacy evaluation of the AMA, there was no significant difference (P>0.05) between the treatments with and without additive at the tested levels of inclusion. Thus, β-ZAL may be employed as a biomarker of ZEN exposure via diet to evaluate the efficacy of an AMA through serological parameters. The technique applied in this study proved to be an adequate alternative for in vivo confirmation of the efficacy of products in adsorbing the toxin.