Calculate of withdrawal times of clenbuterol in goats to obtain safe times of slaughter

BACKGROUND AND AIM: Clenbuterol as a β(2)-agonist drug was investigated according to the concentration of the drug available in the bodies of goats and according to the level of sensitivity of the instruments used for detection. The objective of the current study was to determine withdrawal times after giving a therapeutic dose that resulted in safe slaughters. MATERIALS AND METHODS: Five healthy male goats with a mean body weight of 20.64 kg were treated with a single dose of 5.10(−3) mg(/)kg in the BW onto jugular vein. Whole blood samples of approximately 5 mL were taken in a time series at 5, 30, 60, 90, 150, 210, 270, 390, 510, 630, and 750 min. At 24 h posttreatment, all subjects were sacrificed, and 300 g samples of the liver were obtained. The plasma concentration and liver residue of the drug were observed by reverse-phase high-performance liquid chromatography. RESULTS: The drug reached a maximum concentration of 19.233±0.331 µg/mL at 5 min, and the elimination half-life was at 173.25 min. The limit detection was obtained at 0.053 µg/mL. A one-way analysis of variance between all goats showed that elimination of the clenbuterol in their bodies was similar (p=1.00), with a withdrawal time of 1,479.326 min and no residues in the liver (p<0.05). CONCLUSION: Safe times for slaughter were determined to be at 2 days, 13 h, and 12 min as the 2(nd) safety factor (SF) time and 3 days, 1 h, and 58 min as the 3(rd) SF time with the liver organ free from residue. elimination half-life, new method for calculating withdrawal time, prescriptions for obtained β(2)-agonist, residues in liver.