INTA EEA Balcarce, Buenos Aires, Argentina.
Vet Parasitol. 2012 Jun 8;187(1-2):237-43. doi: 10.1016/j.vetpar.2011.12.040. Epub 2012 Jan 5.
The study of the anthelmintic properties of plants rich in plant secondary metabolites can provide ecologically sound methods for the treatment of parasites on grazing animals. The purpose of the present study was to evaluate the anthelmintic effect of five tropical native Australian plant species rich in plant secondary metabolites on adult Haemonchus contortus and Trichostrongylus colubriformis in experimentally infected goats. Thirty young, nematode-free goats were infected with 2500 H. contortus and 5000 T. colubriformis infective larvae thrice weekly for a week (day 1-7 of the experiment). On day 27 after first infection, the goats were allocated into six groups of five animals per group. From day 28 to day 35, fresh leaves from Acacia salicina, Acacia nilotica, Eucalyptus corymbia, Casuarina cunninghamiana and Eucalyptus drepanophylla were included in the goats diet. Five groups were offered leaves from one of these plant species and one group, the untreated control, received only the basal diet formulated with 20% Medicago sativa and 80% Avena sativa. Following plant material administration, the goats were monitored daily until day 40 and then slaughtered on day 41. Total faecal worm egg output, total production of larvae recovered from faecal cultures, total post-mortem worm burdens and the per capita fecundity of female worms were estimated. The toxicity of the plant species for the goats was measured by histopathological analyses of liver and kidney samples. Results showed that goats feeding on the plant material rich in plant secondary metabolites had significantly lower egg output compared to the control goats (P<0.05). A similar response was found for larval production in both H. contortus and T. colubriformis supporting that egg output was affected in both species. Although the total worm burdens were not affected by the plant material (P>0.05), the per capita fecundity was significantly reduced by E. corymbia, A. nilotica and A. salicina (P<0.05). No signs of toxicity were detected in the liver or kidney samples. It is concluded that goats can benefit from the short-term ingestion of plant secondary metabolites, which reduce the total faecal egg output and thus decrease the potential for re-infection from the pasture.
本研究旨在评估富含植物次生代谢产物的五种澳大利亚热带本土植物物种对感染放牧动物的寄生蠕虫（如旋毛虫和捻转血矛线虫）的驱虫效果。30 只年轻、无线虫的山羊被感染 2500 条旋毛虫和 5000 条捻转血矛线虫感染性幼虫，每周感染 3 次，持续 1 周（实验第 1-7 天）。首次感染后第 27 天，将山羊分为六组，每组 5 只。从第 28 天到第 35 天，在山羊的饮食中添加新鲜的银荆叶、相思树叶、蓝桉叶、银荆叶和旱柳树叶。五组山羊分别喂食其中一种植物的叶子，一组为未处理的对照组，仅喂食含有 20%紫花苜蓿和 80%燕麦的基础日粮。在进行植物材料处理后，每天监测山羊直至第 40 天，然后在第 41 天进行屠宰。通过粪便培养法估计总粪便虫卵排出量、从粪便培养中回收的幼虫总产量、总死后虫体负荷和雌性虫体的人均产卵量。通过对肝脏和肾脏样本进行组织病理学分析，评估植物物种对山羊的毒性。结果表明，与对照组相比，食用富含植物次生代谢产物的植物材料的山羊的卵产量显著降低（P<0.05）。旋毛虫和捻转血矛线虫的幼虫产量也呈现出相似的反应，这表明两种寄生虫的卵产量都受到了影响。尽管植物材料对总虫体负荷没有影响（P>0.05），但蓝桉叶、相思树叶和银荆叶显著降低了人均产卵量（P<0.05）。在肝脏或肾脏样本中未检测到毒性迹象。综上所述，山羊可以从短期摄入植物次生代谢产物中受益，这可以减少总粪便卵产量，从而降低从牧场重新感染的可能性。
