title: Non-invasive screening for treatment of heifers with the anabolic steroid melengestrol acetate (MGA) by feces analysis.
abstract: For eight weeks, two heifers each had been orally administered daily doses of 0, 1.5, or 5 mg melengestrol acetate (MGA) in a feed premix. Four heifers received the labeled dose of 0.5 mg/day. Regular feces samples were taken throughout the experiment. A rapid screening method for the determination of MGA in feces was developed, consisting of liquid extraction, clean-up on solid-phase extraction cartridges and quantification by enzyme immunoassay (ELISA). Residues in feces were dose-dependent with mean values of < 0.25, 2.0, 4.4, or 15.4 ng/g for 0, 0.5, 1.5, and 5 mg/day doses, respectively. In contrast to urine analysis, feces analysis appeared to be a suitable means of non-invasive screening before slaughter for surveillance of MGA treatment and verification of its compliance with labeled dosage.
authors.affiliation: Institut für Physiologie, TU München-Weihenstephan, Weihenstephaner, Freising-Weihenstephan, Germany. lange@wzw.tum.de
authors.forename: Iris G
authors.initials: IG
authors.lastname: Lange
authors.forename: Andreas
authors.initials: A
authors.lastname: Daxenberger
authors.forename: Melanie
authors.initials: M
authors.lastname: Hageleit
authors.forename: Michael W
authors.initials: MW
authors.lastname: Pfaffl
authors.forename: Heinrich H D
authors.initials: HH
authors.lastname: Meyer
mesh_terms: D000284:Administration, Oral; D045930:Anabolic Agents / Q000008:administration & dosage* / Q000032:analysis*; D000818:Animals; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005243:Feces / Q000737:chemistry*; D005260:Female; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D008552:Melengestrol Acetate / Q000008:administration & dosage* / Q000032:analysis*
chemical_list: D045930:Anabolic Agents; D008552:Melengestrol Acetate