Effects of shook swarm and supplementary feeding on oxytetracycline levels in honey extracted from treated coloniesHelen M. Thompsona, Ruth J. Waitea, Selwyn Wilkinsa, Michael A. Browna, Tim Bigwoodb, Marvin Shawb, Christopher Ridgwayb and Matthew Sharmanb
a National Bee Unit, Central Science Laboratory, Sand Hutton, York, YO41 1LZ, UK
b Veterinary Drug Residue Team, Central Science Laboratory, Sand Hutton, York, YO41 1LZ, UK
(Received 4 January 2005 - revised 21 June 2005 - accepted 21 June 2005 - published online 13 December 2005)
Abstract - This study aimed to assess oxytetracycline (OTC) residue levels in honey up to 12 weeks after treatment of honeybee colonies with two methods of treatment (shook swarm and large volume feeding post-treatment) and two methods of application (in liquid sucrose and in powdered icing sugar). Samples of honey were extracted up to 12 weeks after treatment and analysed by HPLC following metal chelation. Residues in the honey collected from the treated colonies 56 days after treatment (the current withdrawal period) were in excess of the LOQ (0.05 mg kg-1). These data suggest a withdrawal period of up to 16 weeks is required for colonies treated with OTC in liquid sucrose and up to 18 weeks is required for those colonies treated in icing sugar. The data from these experiments have been used as the basis of a recommendation that shook swarm without OTC treatment is the preferred method of EFB control in the UK and if OTC is used then the withdrawal period is extended to 6 months after application.
Key words: Apis mellifera / oxytetracycline / residue / European foulbrood / antibiotic / withdrawal period
Corresponding author: Helen M. Thompson H.Thompson@csl.gov.uk
© INRA, DIB-AGIB, EDP Sciences 2005