Residues depletion in egg after warfarin ingestion by laying hens.

Accidental ingestion of anticoagulant rodenticide bait by poultry rarely leads to clinical signs of poisoning, but represents a risk for the consumer because of potential residues in the laid eggs. An assay was conducted for a better risk assessment. Three groups of laying hens were given a single oral dose of 10, 30 or 90 mg warfarin/kg BW. Eggs were collected for 14 d, and warfarin was analyzed by reversed-phase high-performance liquid chromatography. Warfarin was present in the white for 3 to 4 d following anticoagulant ingestion, while concentration increased in the yolk until the 5th or 6th d, and then gradually decreased. At the end of experimentation, warfarin was still detected at below 100 ng/g in the yolk of eggs in each group.