- 1Ghent
University, Faculty of Veterinary Medicine, Department of Veterinary
Public Health and Food Safety, Laboratory of Chemical Analysis,
Merelbeke, Belgium.
- 2L.C.H., Laboratoire des Courses Hippiques, Verrières-le-Buisson, France.
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.
Copyright © 2016 John Wiley & Sons, Ltd.
KEYWORDS:
UHPLC-MS/MS; anabolic steroids; feed; horse; moulds
