BACKGROUND To address a lack of information on the control of ovine helminth parasites in Northern Ireland (NI), a number of research projects have been undertaken, dealing with gastrointestinal nematodes, tapeworms and liver fluke. This investigation concerns Nematodirus and concentrates on three aspects of disease: farm management strategies for its control, derived from the results of a Questionnaire; the efficacy of treatment used by farmers, as determined by a coprological survey; and the hatching requirements of Nematodirus eggs, that is, whether prolonged chilling is a pre-requisite for hatching. RESULTS A Questionnaire was sent to 252 sheep farmers in NI in March 2012 (covering the years 2009-2012) and replies were received from 228 farmers. Under-dosing, inaccurate calibration of equipment and inappropriate product choice were poor practices identified. Following this survey, the efficacy of treatment of Nematodirus spp. in sheep flocks was evaluated in April and May 2012. Sampling kits were sent to 51 flock owners, all of whom returned pre- and post-anthelmintic dosing faecal samples to the laboratory for analysis. At the time of treatment, 41 flocks were positive for Nematodirus (as diagnosed by the presence of eggs). Reduced benzimidazole efficacy was detected in 35.7% of flocks tested (n = 28). Although only involving a small number of flocks, reduced efficacy of levamisole treatment was detected in 50%, of avermectins in 33% and of moxidectin in 75% of flocks tested (n = 2, 6 and 4, respectively). In the egg hatch experiment, carried out under "chilled" and "non-chilled" conditions, 43% of the eggs in the "non-chilled" group were able to hatch, compared to 100% in the "chilled" group. CONCLUSIONS The identification of inefficient control strategies argues for continued education of stockholders, in order to improve their management programmes. This is particularly important where the practices might impact on the development of anthelmintic resistance, which has been shown to exist on NI farms. The appropriate choice of anthelmintic is a vital part of this plan. The ability of eggs to hatch under non-chilled conditions demonstrates a flexibility in hatching behaviour. This may represent an adaptation to climate change and account for the recent emergence of a second, autumnal peak of infection.

中文翻译：

---

线虫属的控制。北爱尔兰的羊群主人感染。


背景技术为了解决北爱尔兰（NI）缺乏关于控制绵羊蠕虫寄生虫的信息，已经开展了许多研究项目，涉及胃肠道线虫、绦虫和肝吸虫。这项调查涉及线虫，集中于疾病的三个方面：根据调查问卷结果得出的控制其控制的农场管理策略；通过粪便调查确定农民使用的治疗效果；以及线虫卵的孵化要求，即长时间冷藏是否是孵化的先决条件。结果 2012 年 3 月，向北卡罗来纳州 252 名养羊户发出了一份调查问卷（涵盖 2009-2012 年），并收到了 228 名养羊户的答复。剂量不足、设备校准不准确和产品选择不当是不良做法。根据这项调查，线虫属的治疗效果。 2012 年 4 月和 5 月对羊群中的感染情况进行了评估。采样套件已发送给 51 名羊群主人，所有这些羊群在服用驱虫药之前和之后的粪便样本都返回实验室进行分析。在治疗时，41 只鸡群的线虫呈阳性（根据卵的存在进行诊断）。 35.7% 的测试鸡群 (n = 28) 检测到苯并咪唑功效降低。尽管仅涉及少量鸡群，但在测试的鸡群中，50% 检测到左旋咪唑治疗效果降低，33% 检测到阿维菌素治疗效果降低，75% 检测到莫昔克汀治疗效果降低（分别为 2、6 和 4）。在“冷藏”和“非冷藏”条件下进行的鸡蛋孵化实验中，“非冷藏”组中 43% 的鸡蛋能够孵化，而“冷藏”组中这一比例为 100%。 结论 识别低效控制策略需要对股东进行持续教育，以改进其管理计划。当这些做法可能会影响驱虫药耐药性的发展时，这一点尤其重要，这种耐药性已被证明存在于北爱尔兰农场。适当选择驱虫药是该计划的重要组成部分。鸡蛋在非冷冻条件下孵化的能力表明了孵化行为的灵活性。这可能代表了对气候变化的适应，并解释了最近出现的第二个秋季感染高峰。