title: Mouldy feed: A possible explanation for the excretion of anabolic-androgenic steroids in horses.
abstract: To ensure fair competition and to protect the horse's welfare, horses have to compete on their own merits, without any unfair advantage that might follow the use of drugs. Therefore, regulatory authorities list all substances that are not allowed in competition, including most anabolic-androgenic steroids. As zero-tolerance is retained, the question arose whether the consumption of mouldy feed could lead to the excretion of steroids, due to the biotransformation of plant phytosterols to steroids. A rapid ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analytical method, previously validated according to AORC (Association of Official Racing Chemists) and EC (European Commission) guidelines, was used to measure steroids in different sample types. Multiple mouldy feed samples were tested for the presence of steroids. The effect of digestion was tested by in vitro simulation of the horse's hindgut in batch incubations. In most feed samples no steroids were detected, even when the products were mouldy. Mouldy corn however showed to contain up to 3.0 ± 0.4 µg/kg AED (4-androstenedione), the main testosterone precursor. This concentration increased when mouldy corn (with added phytosterols) was digested in vitro. An herbal phytosupplement also showed to contain α-testosterone. These results demonstrate that it is important to caution against the consumption of any feed or (herbal) supplement of which the detailed ingredients and quantitative analysis are unknown. The consumption of mouldy corn should especially be avoided, not only from a horse health and welfare point of view, but also to avoid possible inadvertent positive doping results. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Ghent University, Faculty of Veterinary Medicine, Department of Veterinary Public Health and Food Safety, Laboratory of Chemical Analysis, Merelbeke, Belgium.
authors.forename: A I
authors.initials: AI
authors.lastname: Decloedt
authors.affiliation: L.C.H., Laboratoire des Courses Hippiques, Verrières-le-Buisson, France.
authors.forename: L
authors.initials: L
authors.lastname: Bailly-Chouriberry
authors.affiliation: Ghent University, Faculty of Veterinary Medicine, Department of Veterinary Public Health and Food Safety, Laboratory of Chemical Analysis, Merelbeke, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Vanden Bussche
authors.affiliation: L.C.H., Laboratoire des Courses Hippiques, Verrières-le-Buisson, France.
authors.forename: P
authors.initials: P
authors.lastname: Garcia
authors.affiliation: L.C.H., Laboratoire des Courses Hippiques, Verrières-le-Buisson, France.
authors.forename: M-A
authors.initials: MA
authors.lastname: Popot
authors.affiliation: L.C.H., Laboratoire des Courses Hippiques, Verrières-le-Buisson, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Bonnaire
authors.affiliation: Ghent University, Faculty of Veterinary Medicine, Department of Veterinary Public Health and Food Safety, Laboratory of Chemical Analysis, Merelbeke, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Vanhaecke
mesh_terms: D000332:Aerobiosis; D045930:Anabolic Agents / Q000032:analysis* / Q000378:metabolism / Q000652:urine; D000728:Androgens / Q000032:analysis* / Q000378:metabolism / Q000652:urine; D000821:Animal Feed / Q000032:analysis* / Q000382:microbiology*; D000818:Animals; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019587:Dietary Supplements / Q000032:analysis / Q000382:microbiology; D004300:Doping in Sports; D005243:Feces / Q000737:chemistry*; D006736:Horses / Q000378:metabolism / Q000652:urine*; D009089:Mucor / Q000378:metabolism; D009161:Mycobacterium / Q000378:metabolism; D010840:Phytosterols / Q000032:analysis / Q000378:metabolism / Q000652:urine; D013256:Steroids / Q000032:analysis* / Q000378:metabolism / Q000652:urine; D053719:Tandem Mass Spectrometry / Q000379:methods; D013739:Testosterone / Q000032:analysis / Q000378:metabolism / Q000652:urine; D003313:Zea mays / Q000737:chemistry / Q000382:microbiology
chemical_list: D045930:Anabolic Agents; D000728:Androgens; D010840:Phytosterols; D013256:Steroids; D013739:Testosterone
keywords: UHPLC-MS/MS; anabolic steroids; feed; horse; moulds