Reporting from a recent poultry symposium in Chapeco, Brazil the author describes the establishment of controls for nitrofurans, how residues in food products can be prevented and what the poultrymeat exporters of Thailand and Brazil are doing to ensure their products are free of contamination. Despite bans on nitrofurans imposed in many industrialised countries from the mid-1990s onwards, extensive illegal use of these compounds in intensive animal production has persisted. Withdrawal of nitrofurans was predicated by the proven genotoxicity and carcinogenic potential of the family of therapeutic compounds and their metabolites. Widespread use in livestock over three decades was based on relatively low cost, antibacterial efficacy, anti-protozoalactivity, universal availability and the absence of a sensitive detection system for residues. When furazolidone is incorporated in poultry feed at a therapeutic dose of 400g/t, the parent drug can only be detected in kidney tissue for approximately sixhours after withdrawal. In contrast, the metabolite AOZ (see Table 1) is extremely stable and can be assayed down to a level of lOppb for up to six weeks following drug withdrawal.
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