Vercruysse J, Dorny P, Hong C, Harris T J, Hammet N C, Smith D G, Weatherley A J
Faculty of Veterinary Medicine, Department of Parasitology, Gent, Belgium.
Vet Parasitol. 1993 Jul;49(1):51-9. doi: 10.1016/0304-4017(93)90223-a.
Two studies were performed to investigate the efficacy of doramectin in the prevention of infection with Ostertagia ostertagi and Cooperia oncophora in grazing calves. In each study, 24 parasite-naive calves were randomly allotted to two equal groups and treated with either doramectin at 200 micrograms kg-1 or saline prior to mid-season turnout (Day 0) onto contaminated pasture. Faecal egg counts were carried out twice weekly from 15 to 64 days after turnout and the cumulative faecal egg count was calculated for each group of calves. In the doramectin-treated animals, eggs first appeared in the faeces 19 days and 22 days later than in controls for Studies 1 and 2, respectively. Mean cumulative faecal egg counts over the 64 days were reduced in the doramectin-treated groups by 71% and 87% for Studies 1 and 2, respectively (P < 0.01). The potential utility of injectable doramectin in the seasonal control of gastrointestinal nematode infestations in relation to these findings is discussed.
开展了两项研究，以调查多拉菌素对放牧犊牛预防感染奥斯特他线虫和牛古柏线虫的效果。在每项研究中，将24头未感染寄生虫的犊牛随机分为两组，在季节中期（第0天）转入受污染牧场之前，一组用200微克/千克的多拉菌素处理，另一组用生理盐水处理。在转入牧场后的第15至64天，每周进行两次粪便虫卵计数，并计算每组犊牛的累积粪便虫卵计数。在多拉菌素处理的动物中，研究1和研究2中，粪便中首次出现虫卵的时间分别比对照组晚19天和22天。在64天内，多拉菌素处理组的平均累积粪便虫卵计数在研究1和研究2中分别降低了71%和87%（P<0.01）。结合这些研究结果，讨论了注射用多拉菌素在季节性控制胃肠道线虫感染方面的潜在效用。
