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Swine Xenobiotics: Detection and Withdrawal Times


1. To validate a non-invasive, detection system using whole blood and fresh fecal samples to confirm exposure of swine to bromadiolone rodenticides.
<P>2. To examine the depletion of whole blood and fecal residue levels over time with those of muscle (loin), skin and adhering fat, and liver bromadiolone concentrations following oral exposure, in order to establish a relationship between tissues. This will enable estimations of residue withdrawal times using whole blood and feces samples based on current AHL validated limits of analytical quantification (limit of detection) of liver bromadiolone levels (0.5 mg/kg or 5 ppm). The liver is the organ of accumulation of rodenticides in swine. We will also follow coagulation profile abnormalities by measuring prothrombin time (PT) and partial thromboplastin time (PTT) in all animals following dosing.

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Expected Benefits:<br/>

Information confirming exposure and tissue depletion (withdrawal times) of bromadiolone in suspected swine toxicities will provide substantial guidance to veterinarians and producers regarding the need for animal disposal and accompanying financial losses, as well as enhanced consumer food safety.
The discovery of rodenticide residues in edible tissues of hogs that are raised in Ontario would create large adverse effects on the reputation of Ontario swine producers and Ontario pork. Ontario exports more than half of its pork to over 70 countries, and a loss of confidence in our product by our trading partners would have significant adverse economic consequences.

A non-invasive detection system confirming exposure, as well as guidance on withdrawal times for exposed animals, is needed in order to ensure food safety while limiting economic losses to producers.

Johnson, Ron
University of Guelph
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