中文摘要：

应用多拉菌素注射剂和伊维菌素浇泼剂微量给药，对自然感染皮蝇幼虫的犊牦牛进行驱虫效力研究。结果：给药后28～34d剖检和翌年3、5月份两次摸背检查远期防治效果，多拉菌素注射剂5μg/kg剂量组驱净率分别为85．0％和92．1％。驱虫率分别为93．6％、93．7％；10、20μg/kg剂量组均为100．0％。伊维菌素浇泼剂12．5μg/kg。剂量组驱净率分别为85．0％和91．2％，驱虫率分别为93．3％和93．2％；25、50μg/kg剂量组均为100．0％。对照组牦牛皮蝇1期幼虫感染率85．0％，平均感染强度29．7条；背部皮下瘤疱和皮肤虫孔的平均感染率84．1％，瘤疱和虫孔总数205个。试验证明供试两种药物使用微量驱除牦牛皮蝇1期幼虫高效安全经济，多拉菌素的最佳剂量为10μg/kg，伊维菌素的最佳剂量为25μg/kg。

英文摘要：

The deworming effect was studied by using deramectin injection and iverrnectin pour-on solution in a small dose in yak calves which were naturally infected by cattle grub. The results of autopsy in the period of 28 - 34 days after administration and palpation of the back of yak in March and May of next year showed that the deworming clean rate and the deworming rate in the yaks of doramectin group in a dose of 5μg/kg were 85.0% and 92.1%, 93.6% and 93.7%, respectively, and in adose of 10μg/kg and 20μg/kg were all 100.0%. The dewomaing clean rate and the deworming rate in the yaks of ivermectin group in a dose of 12.5μg/kg were 85.0% and 91.2% ,93.3% and 93.2%, respectively, and in a dose of 25μg/kg and 50μg/kg were all 100.0% .The infectious rate of first-in.star grub in the yaks of control group was 85.0% and the average infectious intensity was 29.7. The average infectious rate of subcutaneous warbles and the number of skin hole of parasites were 84. 1% and the total number of warbles and parasite holes was 205. This experiment results proved that both doramectin and ivermectin in a small dose were effective,safe and economic for deworming the first-instar grub.The optimum dose of doramectin was 10μg/kg and of ivermectin was 25μg/kg.