Residues of zearalenone (ZEN), deoxynivalenol (DON) and their metabolites in plasma of dairy cows fed Fusarium contaminated maize and their relationships to performance parameters

A feeding trial with dairy cows fed graded proportions of a Fusarium toxin contaminated maize containing mainly deoxynivalenol (DON) was carried out to relate the plasma levels of DON, zearalenone (ZEN) and their metabolites to the performance. German Holstein cows (n = 30) were divided into three groups (n = 10 in each): CON (0.02 mg ZEN and 0.07 mg DON, per kg dry matter, DM), FUS-50 (0.33 mg ZEN and 2.62 mg DON, per kg DM), FUS-100 (0.66 mg ZEN and 5.24 mg DON, per kg DM). The average performance level was characterised by daily DM intake, energy balance and milk yield which were not affected by the DON and ZEN levels in feed. DON, de-epoxy-DON (de-DON) and ZEN were detected simultaneously in all plasma samples. A linear relationship between toxin intake and plasma levels could be established. Moreover, a linear relationship between DON and de-DON concentration could be derived. It was concluded that DON and ZEN intake of 0.5 mg ZEN/kg and 5 mg DON/kg (current guidance values) had no considerable effects on the performance parameter of dairy cows. Furthermore, increased plasma concentrations of ZEN, DON and de-DON may hint on toxin exposure through the diets.