Abstract

RESIDUE DEPLETION OF TILMICOSIN IN CHICKEN TISSUES

Abdelrahman Mostafa*, Nuha M. A. Agbna, Samia A. Wahab and Sania Shaddad

Abstract

The study aimed to assess depletion of residues of tilmicosin in chicken tissues following oral administration of the drug via drinking water. Thirty broiler chickens four weeks old were administered tilmicosin in drinking water for five consecutive days at a dose of 75.0 mg/l. Six birds were sacrificed at day 1, 3,5,7,9, and 12 after withdrawal of the drug. Tissue samples from muscle, liver and kidney were collected in sterile plastic containers and stored at –20°C for analysis. The concentration of the drug in different tissues was evaluated using LC-MS/MS. High concentrations were noted in the muscle 401.8μg/Kg, in the liver 3817.5 μg/Kg and in the kidney 1523.0 μg/Kg. at day one after withdrawal of the treatment. The concentration decreased to MRL (75μg/Kg) in the muscle on day 7 from withdrawal, while in the liver it decreased to 604.9 μg/Kg and 180.8μg/Kg in kidney which are below MRL set by EU. On day 9 the concentration in all tissues decreased to below the MRL that set by EU. This study indicates that withdrawal period of tilmicosin in broiler chickens could be 9 days.

Keywords: Residue, Depletion, Tilmicosin, chicken tissues.