Natural Occurrence of Thiouracil in Urine of Livestock in Poland

Natural occurrence of thiouracil in bovine and swine urine in Poland was investigated. Under the national residue control programme, 537 urine samples were tested. In 77 samples (14.3%) thiouracil was detected above decision limit CCα (0.91 μg L^-1), including eight samples over the recommended concentration of 10 μg L^-1. Of the bovine urine samples, 95 and 99 percentiles have thiouracil concentration below 4.50 and 14.85 μg L^-1 ,and of porcine samples below 2.35 and 6.80 μg L^-1, respectively.