Detection of anabolic residues in misplaced implantation sites in cattle

Eight weeks before slaughter, 26 heifers, 2 calves, and 1 steer were implan ted with licensed anabolic preparations at off-label injection sites. After slaughter, 24 of 31 implantation sites (77%) were detected. Residual pelle ts of Revalor H contained a mean of 42.9 mg trenbolone acetate (range 19.8- 57.7 mg) and 4.6 mg (1.96-6.45 mg) estradiol, corresponding to 30% (19.8-57 .7%) and 32.7% (14.0-46.6 %) of the originally applied dose, respectively. In the tissue areas containing residual Revalor H pellets, total residues r anged from 14.8 mu g to 12.6 mg trenbolone acetate, 41.7 mu g to 1.45 mg tr enbolone, and 11.1 mu g to 3.39 mg estradiol. The outer tissue areas of the injection sites contained <2 mu g hormones. The preparations Synovex H, Fi naplix H, Implus S, and Component EC behaved similarly to Revalor H, Residu es of Synovex Plus were low, whereas the Compudose silicone rubber containe d 58.8% of the implanted dose, but left no significant tissue residues. If implantation sites are processed in meat manufacturing, international thres hold levels of the respective substances will be exceeded in tons of meat p roducts.