Zhang Li, Yuan Lijuan, Ye Mengjun, Xiang Jianjun, Dong Yifan, Liao Qiegen, Qiu Suyan, Zhang Dawen, Yu Xiren
Institute of Quality & Safety and Standards of Agricultural Products Research, Jiangxi Academy of Agricultural Sciences, Nanchang, China.
Key Laboratory for Quality and Safety Control of Poultry Products, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Nanchang, China.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2025 Feb;42(2):203-212. doi: 10.1080/19440049.2024.2445784. Epub 2025 Jan 6.
In this study, residue depletion and withdrawal time estimation of tilmicosin were examined in Taihe black-bone silky fowls (TBSFs) after oral administration for three consecutive days at a dose of 75 mg/L in water. The tilmicosin concentrations in liver, kidney, muscle, and skin/fat of TBSFs collected from different time points (0.16, 1, 3, 5, 7, 9, 12, 20, 30, 40 days after last administration) were determined by UPLC-MS/MS. The results indicated that the tilmicosin concentrations in TBSFs tissues varied significantly, and kidney had the highest average concentrations (2604.65 ± 4625.20 μg/kg), followed by liver (1125.54 ± 1479.24 μg/kg), skin/fat (372.81 ± 428.33 μg/kg), and muscle (104.52 ± 143.95 μg/kg). Meanwhile, tilmicosin was still detected in all the four studied tissues (liver, kidney, skin/fat, and muscle) of TBSFs at the last time point (40th day after administration), suggesting that tilmicosin in TBSFs depleted slowly. Based on our experiments, the recommended withdrawal time of tilmicosin for TBSFs after oral administration for three consecutive days at a dose of 75 mg/L in water should be 32 days, which is much longer than the duration specified by Chinese regulatory authorities (10 days), and the abundance of melanin in TBSFs might be responsible for this phenomenon. Hence, a special use and withdrawal procedure of veterinary drugs in TBSFs is needed, and it is essential to focus on potential involvement of melanin in tilmicosin accumulation.
在本研究中，考察了在饮水中以75 mg/L的剂量连续三天口服替米考星后，泰和乌骨丝毛鸡（TBSFs）体内替米考星的残留消除及休药期。通过超高效液相色谱-串联质谱法（UPLC-MS/MS）测定了在不同时间点（末次给药后0.16、1、3、5、7、9、12、20、30、40天）采集的TBSFs的肝脏、肾脏、肌肉和皮肤/脂肪中的替米考星浓度。结果表明，TBSFs组织中的替米考星浓度差异显著，肾脏中的平均浓度最高（2604.65±4625.20 μg/kg），其次是肝脏（1125.54±1479.24 μg/kg）、皮肤/脂肪（372.81±428.33 μg/kg）和肌肉（104.52±143.95 μg/kg）。同时，在最后一个时间点（给药后第40天），TBSFs的所有四个研究组织（肝脏、肾脏、皮肤/脂肪和肌肉）中仍检测到替米考星，这表明TBSFs中的替米考星消除缓慢。基于我们的实验，在饮水中以75 mg/L的剂量连续三天口服替米考星后，TBSFs的推荐休药期应为32天，这比中国监管机构规定的时间（10天）长得多，TBSFs中黑色素的含量可能是造成这种现象的原因。因此，需要制定TBSFs中兽药的特殊使用和休药程序，并且必须关注黑色素在替米考星蓄积中的潜在作用。
