Maingi N, Otieno R O, Weda E H, Gichohi V M
Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
Vet Res Commun. 2002 Oct;26(7):543-52. doi: 10.1023/a:1020291531858.
The efficacy of strategic anthelmintic control of liver flukes (Fasciola) and gastrointestinal (GI) nematodes on the performance of ewes and lambs on pasture was assessed on a farm in the highlands of Kenya. In May 1999, 45 Corriedale ewes, aged between 2 and 3 years, were ear-tagged, weighed and allocated randomly to three equal treatment groups based on body weight. Faecal samples taken at this time revealed low levels of strongyle-type eggs per gram of faeces (EPG) and the presence of liver fluke eggs in only a few of the animals. All the animals were then set stocked for 12 months on separate paddocks in an area endemic for both Fasciola and GI nematodes. The ewes in group 1 were given a combined anthelmintic treatment against Fasciola and GI nematodes during the periods recommended for the control of Fasciola in the area (February, June and October). The ewes in group 2 were given the combined treatments 3 weeks after the onset of both the short and long rainy seasons (November and April, respectively). Those in group 3 were given separate treatments for Fasciola (February, June and October) and nematodes (3 weeks after the onset of the rainy seasons). The anthelmintic treatment against Fasciola consisted of triclabendazole at 10 mg per kg body weight, and that against nematodes was levamisole at 10 mg per kg body weight. The nematode EPG for the ewes in group 1 were higher than in groups 2 and 3 during both rainy seasons. The nematode EPG did not differ significantly between groups 2 and 3. The prevalence of Fasciola eggs (number of ewes shedding eggs in a group) in the ewes in groups I and 3 remained very low throughout the study period compared to those in group 2. The highest birth weights and the weight gains of lambs were recorded for the group of ewes given separate anthelmintic treatments for Fasciola and nematodes (group 3). The results of this trial indicated that, in an area like Nyandarua District, where liver flukes and GI nematodes are important constraints to sheep production, the best practice is to give separate treatments for the two groups of parasites at the recommended times.
在肯尼亚高地的一个农场，评估了肝片吸虫（片形吸虫属）和胃肠道线虫的战略驱虫控制对牧场母羊和羔羊生产性能的影响。1999年5月，45只2至3岁的考力代母羊被戴上耳标、称重，并根据体重随机分为三个相等的处理组。此时采集的粪便样本显示，每克粪便中圆线虫型虫卵（EPG）含量较低，只有少数动物体内存在肝片吸虫卵。然后，所有动物在片形吸虫和胃肠道线虫流行的地区，分别在不同的围场放牧12个月。第1组的母羊在该地区推荐的控制片形吸虫的时期（2月、6月和10月）接受了针对片形吸虫和胃肠道线虫的联合驱虫治疗。第2组的母羊在短雨季和长雨季开始后3周（分别为11月和4月）接受联合治疗。第3组的母羊分别在2月、6月和10月接受片形吸虫治疗，在雨季开始后3周接受线虫治疗。针对片形吸虫的驱虫治疗为每千克体重10毫克三氯苯达唑，针对线虫的驱虫治疗为每千克体重10毫克左旋咪唑。在两个雨季期间，第1组母羊的线虫EPG均高于第2组和第3组。第2组和第3组之间的线虫EPG没有显著差异。与第2组相比，在整个研究期间，第1组和第3组母羊中肝片吸虫卵的流行率（一组中排虫卵的母羊数量）仍然非常低。接受片形吸虫和线虫单独驱虫治疗的母羊组（第3组）的羔羊出生体重和体重增加最高。该试验结果表明，在像尼扬达鲁瓦区这样肝片吸虫和胃肠道线虫对绵羊生产构成重要限制的地区，最佳做法是在推荐时间对两组寄生虫分别进行治疗。
