Marley C L, Cook R, Barrett J, Keatinge R, Lampkin N H
Institute of Rural Sciences, University of Wales, Aberystwyth SY23 3AL, UK.
Vet Parasitol. 2006 Jun 15;138(3-4):280-90. doi: 10.1016/j.vetpar.2006.01.029. Epub 2006 Feb 21.
Two experiments were conducted to investigate the effects of birdsfoot trefoil and chicory on parasitic nematode development, survival and migration when compared with perennial ryegrass. In experiment one, sheep faeces, containing 10,385 Cooperia curticei eggs were added to 25 cm diameter pots containing birdsfoot trefoil, chicory or ryegrass, and the pots maintained under optimal conditions for nematode parasite development. Replicate pots of each forage type were destructively sampled on day 8, 16, 20, 28 and 37 to collect the nematode larvae. When forages were compared on a dry matter basis, by day 16 there were 31% and 19% fewer larvae on birdsfoot trefoil and chicory than on ryegrass, respectively (P<0.01). In the second experiment, replicate 1m(2) field plots of birdsfoot trefoil, chicory and ryegrass were sub-sampled on day 14, 21, 35 and 49 for larval counts following the application of sheep faeces containing 585,000 Teladorsagia circumcincta eggs to each plot on day 0. Results showed there were a minimum of 58% and 63% fewer infective stage parasitic larvae on birdsfoot trefoil and chicory, respectively, compared with ryegrass on day 14 and 35 when forages were compared on a forage dry matter, plot area sampled and leaf area basis (P<0.01). Overall, these results indicate that the number of infective stage larvae on birdsfoot trefoil and chicory pasture was reduced by the effect of their sward structure on the development/survival/migration of ovine parasitic nematodes. These effects may be one of the ways in which these forages may affect parasitic infections in grazing livestock.
进行了两项试验，以研究与多年生黑麦草相比，百脉根和菊苣对寄生线虫发育、存活及迁移的影响。在试验一中，将含有10385枚柯氏古柏线虫虫卵的羊粪便添加到直径25厘米、装有百脉根、菊苣或黑麦草的花盆中，并将花盆置于线虫寄生虫发育的最佳条件下。每种饲草类型的重复花盆在第8、16、20、28和37天进行破坏性采样，以收集线虫幼虫。当以干物质为基础比较饲草时，到第16天，百脉根和菊苣上的幼虫分别比黑麦草上少31%和19%（P<0.01）。在第二项试验中，在第0天向每块1平方米的百脉根、菊苣和黑麦草田间试验地施加含有585000枚环形泰勒线虫虫卵的羊粪便后，于第14、21、35和49天对其进行二次采样以计数幼虫。结果表明，在第14天和35天，当以饲草干物质、采样地块面积和叶面积为基础比较饲草时，与黑麦草相比，百脉根和菊苣上感染阶段的寄生幼虫分别最少减少58%和63%（P<0.01）。总体而言，这些结果表明，百脉根和菊苣牧草地上感染阶段幼虫的数量因它们的草皮结构对绵羊寄生线虫的发育/存活/迁移产生影响而减少。这些影响可能是这些饲草影响放牧家畜寄生虫感染的方式之一。
