Abstract
Veterinary drugs, such as antimicrobial compounds, are widely used in poultry and may lead to the presence of residues in matrices of animal origin, such as muscle and liver tissue. In this study, broilers received an experimental feed containing sulfadiazine or doxycycline at cross-contamination levels of 2.5, 5 and 10% of the therapeutic dose in feed. Breast and thigh muscle and liver samples were collected during treatment and depletion period and analysed via liquid chromatography–tandem mass spectrometry (LC–MS/MS). Concentrations reached a plateau phase 3–5 days after the start of experimental feeding. A rapid depletion of residues was noted after withdrawal of the experimental feed. No significant differences in measured concentrations were observed between the various muscle types. Residue concentrations for some experimental groups; the 10% group of sulfadiazine and the 5 and 10% group of doxycycline, however, exceeded their corresponding maximum residue limits (MRLs).
Acknowledgements
Special thanks to our laboratory personnel: P. De Neve, P. Van Herreweeghe, E. Verween, L. Batjoens and S. Degroote of ILVO's, Technology and Food Science Unit, and to A. Maes and M. Geerinck of Ghent University for their help with the LC–MS/MS analyses. Also thanks to the animal carers: B. Claeys, M. De Cock, J. De Deken, A. De Ruyver, D. Derore, C. Eeckhout and G. Van Den Bossche of ILVO's Animal Sciences Unit for their help with the animal experiments, and to M. Levenson for language correction.