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steroid profiling by gas-chromatography tandem mass spectrometry and multivariate statistics for detection of natural hormone abuse in cattle. Food Additives and Contaminants, 2012, pp.1. <10.1080/19440049.2012 For years it is suspected that natural hormones are illegally used as growth promoters in cattle in the European Union. Unfortunately there is a lack of methods and criteria that can be used to detect the abuse of natural hormones and distinguish treated from non-treated animals. Pattern recognition of steroid profiles is a promising approach for tracing/detecting the abuse of natural hormones administered to cattle. Traditionally steroids are analyzed in urine as free steroid after deconjugation of the glucuronide (and sulphate) conjugates. Disadvantage of this deconjugation is that valuable information about the steroid profile in the sample is lost. In this study we developed a method to analyze steroids at very low concentration levels (ng.L-1) for the free steroid, glucuronide and sulphate conjugates in urine samples. This method was used to determine concentrations of natural (pro)hormones in a large population (n=620) of samples from male and female bovine animals and from bovine animals treated with testosterone-cypionate, estradiol-benzoate, dihydroepiandrosterone and pregnenolone.

Following findings of 17beta-19-nortestosterone (150-200 microg kg(-1)) in pigs of unspecified gender imported into the European Union, a study to determine steroid and hormone levels in swine from six age/gender categories (uncastrated 'old' boars, cryptorchids, one intersex, barrows, gilts and sows) was initiated. Indeed, for some hormones there has been a discussion about their being endo- or exogenous. Tissue and urine samples from swine from each of the six categories were obtained in Belgium, France, the Netherlands and the USA. Samples were analysed in three laboratories. Quantitation was obtained for norandrostenedione, 19-nortestosterone and boldenone. The results give a well-documented overview of the status of the presence of these hormones in swine. The data illustrate that uncastrated 'old' boars produce the highest percentage of 'positive' matrices, followed by the cryptorchids. Concentrations in the matrices of the barrows and the gilts are lower. Also, sow matrices contain low amounts of nor-steroids. Furthermore, urine samples from an intersex pig contains a higher concentration of nortestosterone than sows and can therefore be suspected for illegal use of these hormones. Veterinarians taking samples in pig farms for the analysis of hormones need to be aware of the presence and concentrations of these substances in the different categories.

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