Tissue depletion of tylosin after multiple intramuscular administration in calves and piglets

Abstract

Tylosin (TYL) is widely used to treat different bacterial infections in calves and piglets; however, there is no information available about the withdrawal period necessary for growing calves and piglets to be safe for human consumption. A high-performance liquid chromatography method with ultraviolet-visible light detection was adapted and validated for the determination of TYL in calf and piglet tissues. The procedure is based on the isolation of the TYL compound from edible calf and piglet tissues (muscle, liver, kidneys, and fat with skin) with satisfactory recovery (81.55 ± 10.49) and specificity. The residue depletion of TYL in calves and piglets was assessed after a dose of 10 mg/kg body weight/day administered orally for 5 consecutive days. After the treatment was discontinued, residue concentrations were detected in tissues till the 11th and 19th day in calves and piglets, respectively. The highest TYL concentrations were measured in the liver, in both species. Based on the results presented in this study, it could be assumed that a withdrawal period of 12 days for calves and 20 days for piglets before slaughter would be sufficient to ensure consumer safety.