3种兽药及其主要代谢产物在猪粪中的排泄规律

以磺胺二甲嘧啶、金霉素和泰乐菌素为研究对象，探讨在饲粮中添加兽药后，猪粪中3种兽药原形及其主要代谢产物的排泄规律。试验选取60头33k左右的长大二元杂交母猪，在饲粮中加入200mg／kg的磺胺二甲嘧啶、75mg／kg的金霉素和100mg／kg的泰乐菌素，分用药期和休药期收集猪粪检测其中的兽药原形及其代谢产物残留。结果表明，7d用药期内猪粪中磺胺二甲嘧啶及其主要代谢产物对位氨基乙酰化磺胺二甲嘧啶的平均残留分别为59．50，15．98μg／g；金霉素及其代谢产物4位差向异构金霉素平均残留分别为239．92，217．79μg／g；泰乐菌素A及其代谢产物泰乐菌素D的平均残留分别为10．50，65．99／μg／g。进入休药期后，猪粪中兽药原型及其代谢产物残留下降很快，到休药期结束时，相应试验组的猪粪中已检测不出金霉素及其代谢产物残留，但仍可检出磺胺二甲嘧啶及其代谢产物和泰乐菌素A及其代谢产物。由此可知，兽药的体内代谢产物在兽药的排泄中占重要比例，提示除兽药原形外还应重视其代谢产物进入环境后的生态毒理学效应。

Excretion of sulfamethazine,chlortetracycline, tylosin and their main metabolites in pig manure

Sixty Landrace-Yorkshire hybrid sows weighed about 33 kg were divided randomly into 4 groups. The blank trial was treated by the daily ration without any drugs. Other three trials were treated by the daily ration containing sulfadimethoxine （200 mg/kg）,chlortetracycline （75 mg/ kg） ,and tylosin （100 mg/kg） ,respectively. Pig manure was collected in application time and with drawal time of drugs. The results showed that the average concentration of sulfadimethoxine （SM2） and its main metabolite N4-ACE- SM2 ,chlortetracycline （CTC） and its main metabolite 4- epi-CTC,tylosin and its main metabolite tylosin-D were 59.50/μg/g and 15.98/μg/g,239.92/~g/g and 217. 79μg/g,10.50/μg/g and 65.99/lg/g in the drug application time,respectively. In the with drawal time of drugs, the concentration of drugs and their main metabolites in pig manure de creased sharply. CTC and its main metabolite 4-epi-CTC were not detected in pig manure after the withdrawal time,but SM and N-ACE- SM2, tylosin and tylosin-D were still detected. Because the metabolites were the important constitutional part of the drug excretion in manure,we should em phasize their ecotoxicological effect.