Discovery of urinary biomarkers to discriminate between exogenous and semi-endogenous thiouracil in cattle (Cow samples)

In the European Union, the use of thyreostats for animal fattening purposes has been banned because of their carcinogenic and teratogenic effects, whereby any residues in derived food products may hold a risk for human health. In this regard, potential abuse is monitored by targeted analysis of thyreostats with the application of a zero-tolerance policy. However, such a strategy is no longer adequate because of the semi-endogenous origin of some thyreostats, including thiouracil (TU). Additionally, the use of recommended TU concentration levels (10 or 30 µg/l) is also not fully conclusive. Therefore, this study aimed at defining urinary metabolite markers by which the true origin of detected TU could be ascertained. To this end, an in vivo study was carried out in which 11 calves were subjected to either a control treatment, a rapeseed-enriched diet (known to induce semi-endogenous formation) or a TU treatment. Urine samples (n = 165) were assessed through metabolic fingerprinting, employing ultra-high performance liquid-chromatography and Q-Exactive Orbitrap mass spectrometry. Urinary fingerprints were interpreted by multivariate data-analysis. The targeted Calf samples assay for this study can be found in the MetaboLights study MTBLS554.
Linked Studies: MTBLS554