Heckendorn Felix, Häring Dieter Adrian, Maurer Veronika, Senn Markus, Hertzberg Hubertus
Department of Veterinary Parasitology, Research Institute of Organic Agriculture, Ackerstrasse, CH-5070 Frick, Switzerland.
Vet Parasitol. 2007 May 15;146(1-2):123-34. doi: 10.1016/j.vetpar.2007.01.009. Epub 2007 Mar 1.
We investigated direct anthelmintic effects associated with the feeding of fresh tanniferous forages against established populations of Haemonchus contortus and Cooperia curticei in lambs. Twenty-four parasite naive lambs were inoculated with a single dose of infective larvae of these two parasites 27 days prior to the start of the feeding experiment. Lambs were individually fed with either chicory (Cichorium intybus), birdsfoot trefoil (Lotus corniculatus), sainfoin (Onobrychis viciifolia) or a ryegrass/lucerne mixture (control) for 17 days. Animals where then united to one flock and subjected to control feeding for another 11 days to test the sustainability of potentially lowered egg excretion generated by tanniferous forage feeding. When compared to the control, administration of all tanniferous forages was associated with significant reductions of total daily faecal egg output specific to H. contortus (chicory: 89%; birdsfoot trefoil: 63%; sainfoin: 63%; all tests P<0.05) and a tendency of reduced H. contortus worm burden (chicory: 15%; birdsfoot trefoil: 49% and sainfoin: 35% reduction). Irrespective of the condensed tannin (CT) containing fodder, no anthelmintic effects were found against C. curticei. Cessation of CT-feeding followed by non-CT control feeding did not result in a re-emergence of faecal egg counts based on faecal dry matter (FECDM) in any group, suggesting that egg output reductions are sustainable. The moderate to high concentrations of CTs in birdsfoot trefoil (15.2 g CTs kg(-1) dry matter (DM)) and sainfoin (26.1 g CTs kg(-1) DM) were compatible with the hypothesis that the antiparasitic effect of these forages is caused by their content of CTs. For chicory (3 g CTs kg(-1) DM), however, other secondary metabolites need to be considered. Overall, birdsfoot trefoil and in particular sainfoin seem promising candidates in contributing to an integrated control strategy against H. contortus not only by mitigating parasite related health disturbances of the host but also by a sustained reduction of pasture contamination.
我们研究了给羔羊饲喂新鲜含单宁草料对其体内已建立种群的捻转血矛线虫和柯氏库珀线虫的直接驱虫效果。在饲喂实验开始前27天，给24只未感染过寄生虫的羔羊单剂量接种这两种寄生虫的感染性幼虫。羔羊分别饲喂菊苣（菊苣属）、百脉根（百脉根属）、红豆草（红豆草属）或黑麦草/苜蓿混合物（对照）17天。然后将动物合并为一个群体，再进行11天的对照饲喂，以测试含单宁草料饲喂可能降低的虫卵排泄的可持续性。与对照组相比，所有含单宁草料的饲喂均使捻转血矛线虫的每日粪便总虫卵产量显著降低（菊苣：89%；百脉根：63%；红豆草：63%；所有测试P<0.05），并且捻转血矛线虫的虫体负担有降低趋势（菊苣：15%；百脉根：49%；红豆草：35%降低）。无论含缩合单宁（CT）的饲料如何，均未发现对柯氏库珀线虫有驱虫效果。停止CT饲料饲喂后接着进行非CT对照饲喂，任何组均未导致基于粪便干物质（FECDM）的粪便虫卵计数重新出现，这表明虫卵产量降低是可持续的。百脉根（15.2 g CTs kg(-1)干物质（DM））和红豆草（26.1 g CTs kg(-1) DM）中CT的中高浓度与这些草料的抗寄生虫作用是由其CT含量引起的这一假设相符。然而，对于菊苣（3 g CTs kg(-1) DM），需要考虑其他次生代谢产物。总体而言，百脉根尤其是红豆草似乎是有前景的候选物，不仅有助于通过减轻宿主与寄生虫相关的健康干扰，还通过持续减少牧场污染来制定针对捻转血矛线虫的综合控制策略。
