Dever M L, Kahn L P
School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia; CRC for Sheep Industry Innovation, CJ Hawkins Homestead, University of New England, Armidale, NSW 2351, Australia.
School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
Vet Parasitol. 2015 Apr 30;209(3-4):229-34. doi: 10.1016/j.vetpar.2015.02.018. Epub 2015 Feb 23.
The aim for this experiment was to look for evidence of milk transfer of anthelmintic actives from ewes to their suckling lambs by reference to lambs' faecal worm egg count (WEC). The hypothesis was that WEC will decline in lambs suckling ewes treated with anthelmintics known to be lipophilic. One group of lactating Border Leicester×Merino ewes were treated (TX) with a combination of short (2.5mg/kg monepantel) and long-acting (1mg/kg moxidectin long-acting injection and a sustained release of 4.62g albendazole over 100 days) anthelmintics to remove gastrointestinal nematode (GIN) burden on day 0. The other group of lactating ewes (UTX) and all lambs (White Suffolk sires) were not treated. Ewes and lambs grazed as a single group and were exposed to GIN (predominately Haemonchus contortus) infection from pasture. Measurements were taken on days 0 and 7. WEC of lambs suckling UTX ewes increased from 6441 to 10,341 eggs per gram (epg) between days 0 and 7, while there was a 51% reduction in WEC for lambs suckling TX ewes. Packed cell volume (PCV) was significantly higher for lambs suckling TX ewes on day 7 compared to lambs suckling UTX ewes (28.5% vs. 24.9%, p=0.039). These results suggest that lambs suckling ewes treated with lipophilic anthelmintics received a sub-therapeutic dose via milk which would increase selection within the GIN (H. contortus) population for anthelmintic resistance.
本实验的目的是通过参考羔羊粪便蠕虫卵计数（WEC）来寻找驱虫活性物质从母羊通过乳汁转移至其哺乳羔羊的证据。假设是，哺乳接受已知为亲脂性驱虫药治疗的母羊的羔羊，其WEC会下降。一组哺乳期边境莱斯特×美利奴母羊在第0天接受了短效（2.5mg/kg莫能菌素）和长效（1mg/kg莫昔克丁长效注射剂以及100天内持续释放4.62g阿苯达唑）驱虫药组合治疗（TX），以消除胃肠道线虫（GIN）负荷。另一组哺乳期母羊（UTX）和所有羔羊（白萨福克种公羊）未接受治疗。母羊和羔羊作为一个群体放牧，并暴露于来自牧场的GIN（主要为捻转血矛线虫）感染。在第0天和第7天进行了测量。哺乳UTX母羊的羔羊的WEC在第0天至第7天之间从每克6441个卵增加到10341个卵（epg），而哺乳TX母羊的羔羊的WEC下降了51%。与哺乳UTX母羊的羔羊相比，哺乳TX母羊的羔羊在第7天的红细胞压积（PCV）显著更高（28.5%对24.9%，p = 0.039）。这些结果表明，哺乳接受亲脂性驱虫药治疗的母羊的羔羊通过乳汁接受了亚治疗剂量的药物，这会增加GIN（捻转血矛线虫）群体内对驱虫药耐药性的选择。
