Transfer of nitrofuran residues from parent broiler breeder chickens to broiler progeny.

The use of nitrofuran antibiotics in food-producing animals is prohibited within the EU. Countries in the EU, as well those intending to export food to the EU, must ensure that their products are free from nitrofuran residues. As a result of recent global problems where chicken meat from a wide range of countries has been contaminated with nitrofuran metabolites, an investigation was performed to discover whether or not residues of the nitrofurans might be transferred from parent breeder chickens to their offspring broilers. Four groups of broiler breeders were each treated with one of the nitrofurans: furazolidone, nitrofurazone, nitrofurantoin or furaltadone. Residues of their side-chain metabolites, AOZ, SEM, AHD and AMOZ, were detected in the fertilised eggs at concentrations up to 1567 microg/kg. However, in the chicks that subsequently hatched from these eggs, residue concentrations of SEM, for example, were only found up to 26.6 and 32.5 microg/kg in liver and muscle, respectively, for 1-d-old chicks. Residue concentrations in tissues had fallen below the detection limit of the analytical method for 40-d-old broiler chicks, for all compounds except for semicarbazide (SEM, the nitrofurazone metabolite). Relatively high concentrations of nitrofurans are available to the newly hatched chick through the egg yolk. However, most of these residues are neither utilised nor deposited in the liver or muscle.