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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Animal Metabolism-Agricultural Chemicals Research » Research » Publications at this Location » Publication #351173

Research Project: Detection and Fate of Chemical and Biological Residues in Food and Environmental Systems

Location: Animal Metabolism-Agricultural Chemicals Research

Title: Urinary excretion and tissue residues of zilpaterol HCl after trace-level exposures

item Smith, David
item Shelver, Weilin

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/16/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Zilpaterol HCl is a ß-agonist feed additive approved in the United States to improve feed and growth efficiency of cattle, but its use is banned domestically and internationally in most food animal species and in human and animal competitive events. The objective of this study was to determine levels of zilpaterol exposure that would return positive results using qualitative and quantitative screening and analytical methods. Sheep were fed 1.75 kg of feed containing 0.0075, 0.075, or 0.75 mg/kg of zilpaterol for 12 consecutive days. Urine and tissues were analyzed for zilpaterol residues. Zilpaterol was consistently detected by rapid screening assays (LOD = 1.7 ng/mL) in urine during the dosing and withdrawal periods. Rapid screening assays most consistently detected zilpaterol in tissues of animals exposed to the highest dose. Urine of sheep exposed to 0.0075 mg/kg of dietary zilpaterol consistently tested positive by quantitative LC-MS/MS methods.