Eysker M, Boersema J H, Cornelissen J B, Kooyman F N, de Leeuw W A, Saatkamp H W
Department of Infectious Diseases and Immunology, University of Utrecht, The Netherlands.
Vet Q. 1993 Mar;15(1):20-4. doi: 10.1080/01652176.1993.9694362.
An experiment was carried out with three groups of grazing calves and one housed control group to study the effect of rotational grazing for periods of 1 and 2 weeks on the build up of lungworm and gastro-intestinal nematode infections respectively. The experiment demonstrated that rotational grazing for periods of 1 week on six plots prevented the build-up of heavy lungworm infections. A build up of heavier lungworm infections was observed in a group that was rotationally grazed for periods of 2 weeks on three plots and a group which remained on one plot throughout the grazing season; there was no difference between these two groups. In all three situations, there was an adequate development of immunity against D. viviparus, as measured by worm recovery after challenge infection at the end of the experiment in comparison with worm recovery of the similarly challenged control group. Neither rotational grazing scheme protected the calves against gastrointestinal helminthiasis, because tracer calves, which grazed for 4 days only in August or October, acquired infections which would have resulted in severe illness or even death if necropsy had been postponed for a week.
用三组放牧犊牛和一组舍饲对照犊牛进行了一项实验，以研究分别进行为期1周和2周的轮牧对肺线虫和胃肠线虫感染积累的影响。实验表明，在六个地块上进行为期1周的轮牧可防止严重肺线虫感染的积累。在三个地块上进行为期2周轮牧的一组和在整个放牧季节都留在一个地块上的一组中，观察到较重的肺线虫感染有所积累；这两组之间没有差异。在所有三种情况下，与同样受到攻击的对照组相比，通过实验结束时攻击感染后的虫体回收率来衡量，对胎生网尾线虫都有足够的免疫发育。两种轮牧方案都不能保护犊牛免受胃肠蠕虫病的侵害，因为仅在8月或10月放牧4天的示踪犊牛感染了蠕虫，如果尸检推迟一周，这些感染可能会导致严重疾病甚至死亡。
