Carryover of Maduramicin from Feed Containing Cross-Contamination Levels into Eggs of Laying Hens

Maduramicin is a coccidiostat authorized as feed additive in the European Union for chickens and turkeys for fattening but not for laying hens, considering the risk of residues in eggs. The unavoidable cross-contamination of non-target feed with coccidiostats is regulated by Commission Directive 2009/8/EC and resulting carry-over in food by Commission Regulation (EC) No. 124/2009. To verify the compliance of the maximum levels for maduramicin in feed (50 mu g/kg) and eggs (2 mu g/kg), the carry-over from feed into eggs was investigated. Diets containing 10, 30, and 50 mu g of maduramicin/kg of feed were fed to laying hens. Feed, egg white, and yolk were analyzed by LC-MS/MS. Maduramicin residues were only detected in in egg yolk. Feeding the 10 mu g/kg maduramicin diet resulted in maduramicin concentrations up to 2.5 mu g/kg in whole eggs, already exceeding the maximum level. A carry-over rate of 8% maduramicin from feed into eggs was calculated.