Effects of dietary exposure to zearalenone (ZEN) on carp (Cyprinus carpio L.)

The mycotoxin zearalenone (ZEN) is frequently contaminating animal feedsincluding feed used in aquaculture. In the present study, the effects of dietary exposure toZEN on carp (Cyprinus carpio L.) were investigated. ZEN at three different concentrations(low dose: 332 μg kg−1, medium dose: 621 μg kg−1 and high dose: 797 μg kg−1 final feed,respectively) was administered to juvenile carp for four weeks. Additional groups receivedthe mycotoxin for the same time period but were fed with the uncontaminated diet for twomore weeks to examine the reversibility of the ZEN effects. No effects on growth wereobserved during the feeding trial, but effects on haematological parameters occurred.In addition, an influence on white blood cell counts was noted whereby granulocytes andmonocytes were affected in fish treated with the medium and high dose ZEN diet. In muscle samples, marginal ZEN and α-zearalenol (α-ZEL) concentrations were detected. Furthermore, the genotoxic potential of ZEN was confirmed by analysing formation of micronuclei in erythrocytes. In contrast to previous reports on other fish species, estrogenic effects measured as vitellogenin concentrations in serum samples were not increased by dietary exposure to ZEN. This is probably due to the fact that ZEN is rapidly metabolized in carp.