Application of hormonal growth promoting implant preparations in animal fattening has to take place in observance of Good Vetrinary Practice. Implantation sites reaching the food chain can contaminate whole batches of processed meat. The highest potential risk comes from trenbolone acetate preparations, followed by estradiol or estradiol benzoate, testosterone propionate and progesterone. An evaluation of zeranol was not possible within the scope of this study. After multiple application, treatment with zeranol or testosterone propionate does not cause any infringement of threshold levels in peripheral tissues. Misuse of trenbolone acetate and estradiol benzoate, however, may lead to illicit values. Exceeding of the MRL was found in liver in one out of two animals after treatment with 600 mg and in two out of two animals after treatment with 2000 mg trenbolone acetate. U. S. estradiol threshold levels were violated in the liver and in the kidney even after 3-fold dose of Synovex-H®. Treatment of calves with Synovex-H® or Synovex Plus® led to similar residue levels as after Synovex-H® or Finaplix-H® treatment of heifers. Possible effects of residual hormonal growth promoters in food have to be connected with the overall burden of endocrine disruptors. Attention has to be directed to irreversible effects on prenatal and prepubertal development. The placental transfer of trenbolone, zeranol and melengestrol acetate could be shown in rabbit after residue analysis of fetal tissues. These substances pass the placental barrier and could possibly impair organogenesis in utero.     «

Application of hormonal growth promoting implant preparations in animal fattening has to take place in observance of Good Vetrinary Practice. Implantation sites reaching the food chain can contaminate whole batches of processed meat. The highest potential risk comes from trenbolone acetate preparations, followed by estradiol or estradiol benzoate, testosterone propionate and progesterone. An evaluation of zeranol was not possible within the scope of this study. After multiple application, treatm...     »