Deposition and depletion of decoquinate in eggs after administration of cross-contaminated feed

Abstract

Decoquinate, a chemical coccidiostat used as a feed additive, can occur in eggs due to cross-contamination of feedstuffs for laying hens. An experiment was designed to assess the transfer of decoquinate to hen eggs and its distribution between egg yolk and egg white. Hens were given the feed containing decoquinate at a cross-contamination level (0.34 mg kg^–1) and collected eggs were analysed using an LC-MS/MS method. The plateau level was reached on the eighth day of the experiment and averaged 8.91 µg kg^–1, which is far below the maximum level established at 20 µg kg^–1 for whole eggs. Decoquinate was deposited mostly in egg yolks (26.2 µg kg^–1) and did not deplete completely during 14 days of administration of decoquinate-free feed. The results confirmed that administration of cross-contaminated feed is associated with very low risk of non-compliant residue levels of decoquinate in eggs.

Keywords:

• decoquinate
• residues
• eggs
• feed cross-contamination

Acknowledgements

The authors would like to acknowledge Beata Korycińska, Edyta Protasiuk, Iwona Szymanek-Bany and Konrad Pietruk for performing the laboratory analyses; Bartosz Sell for the veterinary care of the hens during the experiment; and Marcin Nowicki, Cargill Poland, for providing the decoquinate premix.