Study On The Elimination Of Clenbuterol Hydrochloride Residues In Broilers

In this paper, the distribution and elimination of Clenbuterol Hydrochloride (CL) residues in broilers were studied systemically.In this trial, One hundred broilers were randomly assigned into two groups, from the age of 29 days on, both groups of broilers were fed diet added 1 and 3mg/kg CL for 21 days, respectively. 3 broilers were respectively selected from each group at 1d, 2d, 3d, 5d, 7d,10d, 14d, 21d after feeding CL and at 4h, 1d, 2d, 3d, 7d, 14d after withdrawing CL, then the blood of broilers were collected and serum were prepared for measuring the concentration of CL by HPLC. At 4h, 1d, 2d, 3d, 7d, 14d after withdrawing CL, 3 broilers from each group were selected and killed, then the liver, lung, kidney, fat and muscle were sampled, the CL concentrations in these tissues were measured by HPLC. At 1d, 2d, 3d, 5d, 7d, 10d, 14d, 21d after feeding CL and at 4h, 1d, 2d, 3d, 7d, 14d after withdrawing CL, 3 broilers from each group were selected and the feathers of them were collected. The CL concentrations in feathers were measured by GC-MS.The result showed as follows:â‘ CL was absorbed quickly in broilers, it could be detected in serum at the first day of treatment and CL residues of group added 1mg/kg CL reached peak at 5th or 21st day, the CL residues were 33.4ng/mL and 46.4ng/mL respectively. The CL residues of group added with 3mg/kg dietary in serum reached peak at 5d after adding CL and 4h after withdrawing CL, the residual quantities were 40.1ng/mL and 69.1ng/mL respectively. The residue concentration arose with the increase of CL dose and declined gradually after withdraw of CL, with a quick drop in first 3 days.â‘¡There were great differences in CL residues concentration of different tissues in broilers, at 4h after withdraw of CL, the order of CL residue concentration in different tissues was lung > liver > kidney > serum > fat > muscle. The CL residue declined most quickly during the period of 4h to 2d after withdraw of CL, then it declined more slowly during the period of 3d to 13d after withdraw of CL. CL metabolize most quickly in serum, more residue in lung and liver and less residue in fat and muscle. Therefore, the CL residue in muscle could be used to appraise the security of poultry product.â‘¢The CL residue in feather reached peak at 3 days after withdraw of CL, the residues of two groups (1mg/kg, 3mg/kg) were 56.9ng/g and 114.6ng/g respectively. CL residue would increase gradually at 0-3d after withdraw of CL. At 21days, CL residues in feathers of two groups chicken (1mg/kg, 3mg/kg) were 49.6ng/kg and 95.3ng/kg respectively. The residue in feather was different from that in other tissues, CL was easily remained in feather, at the same time, it metabolized slowly with steady residue in the feather.According to the results, we could draw the conclusion that CL was easily remained in tissues of broilers, with wide distribution. It metabolized slowly, the velocity of CL metabolizatin in different tissues were different. Feather is a very proper organ for detecting the CL residue, in addition, liver and lung is also good organs for detecting the CL residue.