School of Agriculture Food and Rural Development, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
Vet Parasitol. 2013 Mar 31;193(1-3):214-22. doi: 10.1016/j.vetpar.2012.10.023. Epub 2012 Nov 12.
We investigated the magnitude of temporal changes in activity, posture and feeding behaviour of cattle infected with Ostertagia ostertagi, and their reversal after treatment with an anthelmintic. Twenty-six, 3-month-old, Holstein-Friesian bulls were allocated to one of three treatment groups. Bulls in two of those (groups P and PA) received 100,000 larvae on three occasions (Days 0, 7 and 14) and the remaining animals served as controls (C). The PA group also received an anthelmintic on Day 31. Parasite eggs appeared in the faeces of P and PA bulls from Day 17; from approximately the same time blood pepsinogen levels increased and body weight (BW) gain decreased (P<0.001). The reduction in BW gain persisted until Day 45 for P animals only. There was a decrease in the number of steps taken for P and PA animals, as well as lying and standing episode frequency, by 41 and 44% respectively (P<0.001) from Day 21 onwards. The average lying and standing episode duration increased by 52 and 55% respectively (P<0.001) from the same time in P and PA compared to C bulls. In addition, meal frequency showed a tendency to decrease for P animals only (P=0.039) from Day 39, and this was the only aspect of feeding behaviour affected by parasitism. All behaviours, returned to control levels within a week of anthelmintic drenching of PA bulls, apart from the number of steps taken. Although BW gain and pepsinogen also started to recover after drenching, these had not returned to control levels by Day 45. The magnitude of the changes in activity, and standing and lying episode frequency and duration suggest that these might have a diagnostic value, especially as all can now be monitored by automated means. However, these behaviours did not show the rapid changes we expected before parasitism manifested clinically and following recovery.
我们研究了感染奥斯特利茨绦虫的牛的活动、姿势和采食行为的时间变化幅度，以及用驱虫药治疗后的逆转情况。26 头 3 月龄荷斯坦-弗里森公牛被分配到三个治疗组之一。其中两组（P 组和 PA 组）在三个时间点（第 0、7 和 14 天）接受了 100,000 条幼虫，其余动物作为对照（C 组）。PA 组还在第 31 天接受了驱虫药治疗。P 和 PA 公牛的粪便中从第 17 天开始出现虫卵；大约从同一时间开始，血液胃蛋白酶原水平升高，体重（BW）增加减少（P<0.001）。P 动物的 BW 增加减少持续到第 45 天。从第 21 天开始，P 和 PA 动物的步数减少，躺卧和站立事件频率分别下降了 41%和 44%（P<0.001）。与 C 组相比，P 和 PA 组的平均躺卧和站立事件持续时间分别增加了 52%和 55%（P<0.001）。此外，只有 P 动物的采食频率有下降的趋势（P=0.039），从第 39 天开始，这是唯一受到寄生虫影响的采食行为方面。PA 公牛用驱虫药治疗一周后，所有行为都恢复到对照水平，除了步数。尽管 BW 增加和胃蛋白酶原也在驱虫后开始恢复，但到第 45 天仍未恢复到对照水平。活动、站立和躺卧事件频率和持续时间的变化幅度表明，这些行为可能具有诊断价值，特别是因为现在所有行为都可以通过自动化手段进行监测。然而，这些行为并没有表现出我们预期的在临床表现和恢复前的快速变化。
