Hooda V, Yadav C L, Chaudhri S S, Rajpurohit B S
Department of Veterinary Parasitology, Haryana Agricultural University, Hisar, India.
J Helminthol. 1999 Jun;73(2):137-42.
Seventy female lambs (6-7 months old) which were exposed to natural infections of Haemonchus contortus were designated as responders or non-responders on the basis of 10 weekly cumulative faecal egg counts. Selected responder and non-responder lambs were treated with ivermectin, housed separately and 6 weeks post-housing, seven lambs from each group were given a trickle infection of Haemonchus contortus at 1000 L3 daily for 5 days per week up to 2 weeks and examined weekly for 10 weeks after first infection. Analysis of data revealed significantly lower mean faecal egg counts and non-significantly less weight loss in responder than non-responder lambs. Mean values of haemoglobin, packed cell volume, total serum protein and peripheral eosinophil counts were significantly higher in responders than non-responders. In contrast, serum pepsinogen concentration was significantly less in responders than in non-responders. At 10 weeks post-infection, there were fewer pathological lesions and significantly lower worm burdens in responders than in non-responders. These results demonstrate a distinct resistance in responders to Haemonchus contortus infection.
70只6至7月龄的雌性羔羊自然感染捻转血矛线虫，根据连续10周的粪便虫卵累计计数，将其分为反应者或无反应者。挑选出的反应者和无反应者羔羊用伊维菌素进行治疗，分开饲养，饲养6周后，每组7只羔羊每周5天每天接种1000条感染性三期幼虫的捻转血矛线虫，持续2周，首次感染后每周检查10周。数据分析显示，反应者羔羊的平均粪便虫卵计数显著低于无反应者，体重减轻不显著。反应者的血红蛋白、红细胞压积、总血清蛋白和外周嗜酸性粒细胞计数的平均值显著高于无反应者。相反，反应者的血清胃蛋白酶原浓度显著低于无反应者。感染后10周，反应者的病理损伤较少，虫负荷显著低于无反应者。这些结果表明反应者对捻转血矛线虫感染具有明显的抵抗力。
