Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 23, 2005
Publication Date: April 15, 2005
Citation: Smith, D.J., Anderson, R.C., Ellig, D.A., Larsen, G.L. 2005. Tissue distribution, elimination, and metabolism of dietary sodium [36Cl]chlorate in beef cattle. Journal of Agricultural and Food Chemistry 53:4272-4280. Interpretive Summary: Each year thousands of US consumers become ill because they have eaten food products that are contaminated with pathogenic bacteria. Intense efforts have been made during the last decade to eliminate pathogenic contamination from food animals. To date, no single strategy to eliminate pathogens from food animal products has been widely accepted. A new pre-harvest food safety strategy has been developed that has been shown to greatly reduce, or even eliminate gram-negative pathogens from cattle. Use of this new feed additive has not been approved by regulatory organizations because it is not known whether residues present in edible tissues of treated animals represent a health risk. The purpose of this study was to provide preliminary data to assess whether residues would preclude the safe use of the product in cattle. Results of this preliminary study indicate that further development of the product is warranted because residues of the parent compound were fairly low and because the major metabolite, chloride, is naturally present in all life forms.
Technical Abstract: Two steers (~195 kg) were each dosed with 62.5 or 130.6 mg/kg body weight sodium [36Cl]chlorate for three consecutive days. All excreta were collected during the dosing and 8-h withdrawal periods. Apparent radiochlorine absorption was 62 to 68% of the total dose with the major excretory route being urine. Parent chlorate was 65 to 100% of the urinary radiochlorine; chloride was the only other radiochlorine species present. Similarly, residues in edible tissues were composed of chloride and chlorate with chloride being the major radiolabeled species present. Chlorate represented 28 to 57% of the total radioactive residues in skeletal muscle; in liver, kidney, and adipose tissues, chlorate ion represented a smaller percentage of the total residues. Chlorate residues in the low dose steer were 26 ppm in kidney, 14 ppm in skeletal muscle, 2.0 ppm in adipose tissue, and 0.7 ppm in liver. These data indicate that sodium chlorate may be a viable pre-harvest food safety tool for use by the cattle industry.