Nansen P, Steffan P E, Christensen C M, Gasbarre L C, Monrad J, Grønvold J, Henriksen S A
Department of Veterinary Microbiology, Royal Veterinary and Agricultural University, Frederiksberg C, Denmark.
Int J Parasitol. 1993 Aug;23(5):627-38. doi: 10.1016/0020-7519(93)90169-y.
The present studies were designed to investigate whether experimental, mixed trichostrongyle infections of stabled calves prior to their first grazing season could confer sufficient immunity to significantly reduce egg excretion after turnout, and thereby prevent loss-producing infections later on. The study comprised four groups, each of seven calves. During spring, two of the groups received two different dose levels of infective larvae twice weekly, and one group received larger larval doses at monthly intervals. One group served as non-experimentally exposed controls. In May all groups grazed separately on similarly contaminated plots. All experimental groups had reduced egg counts, and herbage infectivity of their plots was significantly lower than that of the controls. These findings were reflected in serum pepsinogen levels and in specific serum antibody responses. Additionally, clinical disease was only observed in the control group animals.
本研究旨在调查圈养小牛在第一个放牧季节之前进行的实验性混合毛圆线虫感染是否能产生足够的免疫力，以显著减少放牧后虫卵的排泄，从而预防后期产生损失的感染。该研究包括四组，每组七头小牛。在春季，其中两组每周两次接受两种不同剂量水平的感染性幼虫，一组每月接受较大剂量的幼虫。一组作为非实验性暴露对照组。5月，所有组分别在污染程度相似的地块上放牧。所有实验组的虫卵计数均有所减少，其地块的牧草感染性明显低于对照组。这些结果反映在血清胃蛋白酶原水平和特异性血清抗体反应中。此外，仅在对照组动物中观察到临床疾病。
