SURVEY OF THE HORMONES USED IN CATTLE FATTENING BASED ON THE ANALYSISOF BELGIAN INJECTION SITES

Although the illegal use of orally administered compounds in cattle fa ttening has gained popularity, injection sites are still frequently fo und during control experiments on the carcasses in the slaughterhouses . The high concentrations of hormones in injection sites enable screen ing for the presence of 39 different hormones by a simple extraction f ollowed by a fast and simple high-performance thin-layer chromatograph y analysis. Analysis of injection-site tissue is particularly successf ul for determining the hormones that are illegally injected. This data can not be obtained by analysis of other biological matrices like fae ces, kidney fat or urine, owing to metabolization and selective excret ion and/or deposition of these compounds. Since 1989, over 2000 inject ion sites have been analysed in our laboratory, which yielded a good s urvey of the hormones that were illegally injected. Over this period, the natural hormones estradiol and testosterone (mostly present as the ir esters) have obviously been used extensively. It is clear that sinc e 1990 clostebol acetate has remained the most abused exogenous hormon e. Additionally, some distinct trends were noticed, e.g., a tendency t owards a highly decreased use of nandrolone, an increased use of proge sterone and an increased occurrence of certain androgens like stanozol ol and fluoxymesterone.