Antibiotics administered to livestock are partly excreted with urine and feces. As livestock excrement is used as manure on agricultural fields, soil may be contaminated by excreted antibiotics, potentially resulting in the development of antibiotic-resistant bacteria. Therefore, it is necessary to determine the amount of antibiotic administered to livestock that could spread to agricultural fields through manure application. This study reveals the excretion ratio of tylosin from sheep. After developing an analysis procedure for tylosin in urine and feces from sheep, a tylosin excretion study was performed with two sheep. Tylosin was excreted in urine and feces for four days, after which its concentrations dropped below the limits of quantification (urine: 0.5 μg/kg, feces: 2.4 μg/kg). The total excretion ratio was 11% on average. The results of our study can provide useful knowledge for treating excrement in order to prevent the spread of antibiotics to agricultural fields through manure application.

施用给牲畜的抗生素会与尿液和粪便一起排泄。由于牲畜粪便被用作农田的肥料，土壤可能会被排泄的抗生素污染，从而可能导致产生抗药性细菌。因此，有必要确定施用给牲畜的抗生素的数量，这些抗生素可能通过施用肥料传播到农田。这项研究揭示了绵羊中泰乐菌素的排泄率。在制定了绵羊尿液和粪便中泰乐菌素的分析程序后，对两只绵羊进行了泰乐菌素排泄研究。泰乐菌素在尿液和粪便中排泄四天，之后其浓度降至定量限以下（尿液：0.5μg/ kg，粪便：2.4μg/ kg）。总排泄率平均为11％。