Högberg Niclas, Lidfors Lena, Hessle Anna, Arvidsson Segerkvist Katarina, Herlin Anders, Höglund Johan
Swedish University of Agricultural Sciences, Department of Biomedical Sciences and Veterinary Public Health, Parasitology Unit, Sweden.
Swedish University of Agricultural Sciences, Department of Animal Environment and Health, Sweden.
Vet Parasitol X. 2019 May 8;1:100011. doi: 10.1016/j.vpoa.2019.100011. eCollection 2019 May.
We investigated the effects of gastrointestinal nematode (GIN) challenge on activity patterns in first season grazing (FSG) steers exposed to two different levels of and . At turn-out, experimental animals were allocated to one of two treatment groups grazing in different enclosures each with 32 animals. The first group (High) received 5000 third stage (L3) (50%) and (50%) larvae; whereas the second group (Low) were dewormed monthly with 0.5 mg ivermectin (Noromectin®, Pour-on) per kg bodyweight. Activity patterns were monitored by fitting some animals in each group (High, 10; Low, 8) with leg mounted sensors (IceTag® 3D-accelerometers) during three two-week periods. In animals fitted with sensors body weight gain (BWG) was recorded every fortnight, whereas faecal and blood samples were collected every four weeks for nematode faecal egg count (FEC) and serum pepsinogen concentrations (SPC). Differences between the periods in daily ( = 0.046) and diurnal ( = 0.0502) activities were recorded between groups during the course of the study. A significant ( = 0.038) increase in the number of lying bouts was recorded in group High during the second period (days 74-86), which was correlated (r = 0.55, = 0.018) to an increase in SPC ≈ 85 days after turn-out. BWG was reduced ( = 0.037) in group High compared to group Low, deviating from day 45. Strongyle nematode eggs were observed in both groups 29 days after turn-out, however the mean EPG remained low in group Low throughout the experiment. An increase in SPC was observed ( < 0.0038) in group High with levels peaking on day 58. In conclusion, our data supports that changes in activity patterns monitored with sensors could contribute to the identification of animals challenged with GIN, but also improve our understanding in the potential welfare impairments caused by such infections.
我们研究了胃肠道线虫（GIN）感染对第一季放牧（FSG）期肉牛活动模式的影响，这些肉牛暴露于两种不同水平的[未提及具体物质]。在放牧开始时，将实验动物分配到两个处理组之一，分别在不同围栏中放牧，每个围栏有32只动物。第一组（高剂量组）接受5000条第三期（L3）[未提及具体线虫种类]（50%）和[未提及具体线虫种类]（50%）幼虫；而第二组（低剂量组）每月按每千克体重0.5毫克伊维菌素（诺莫菌素®，浇泼剂）进行驱虫。在三个为期两周的时间段内，通过给每组中的一些动物（高剂量组10只；低剂量组8只）佩戴腿部安装的传感器（IceTag® 3D加速度计）来监测活动模式。对于佩戴传感器的动物，每两周记录一次体重增加（BWG），而每四周采集粪便和血液样本，用于线虫粪便虫卵计数（FEC）和血清胃蛋白酶原浓度（SPC）检测。在研究过程中，记录了两组之间每日（P = 0.046）和昼夜（P = 0.0502）活动在不同时间段的差异。在第二个时间段（第74 - 86天），高剂量组的躺卧次数显著增加（P = 0.038），这与放牧开始后约85天SPC的增加相关（r = 0.55，P = 0.018）。与低剂量组相比，高剂量组的BWG从第45天开始降低（P = 0.037）。放牧开始29天后，两组均观察到圆线虫卵，但在整个实验过程中，低剂量组的平均每克粪便虫卵数（EPG）一直较低。高剂量组观察到SPC增加（P < 0.0038），在第58天达到峰值。总之，我们的数据支持这样的观点，即通过传感器监测到的活动模式变化有助于识别受GIN感染的动物，同时也能增进我们对这种感染可能导致的潜在福利损害的理解。
