Borgsteede F H, Eysker M
Vet Parasitol. 1987 Apr;24(1-2):93-101. doi: 10.1016/0304-4017(87)90134-8.
A field study was undertaken of the possible differences in propensity for inhibited development in strains of cattle nematodes from two different locations in The Netherlands. In one location (Lelystad) the strains were thought to lack the ability for inhibited development as a result of environmental stimuli on the infective larvae, while in the other location (Utrecht) this ability was presumed to be present. The Lelystad strains were kept at the original location and were also transferred to a pasture in Utrecht, while the Utrecht strains remained in Utrecht. At both locations all permanent grazing calves showed high proportions of inhibited early fourth stage larvae of Ostertagia ostertagi, the proportion of the Utrecht strain being higher than the local and the transferred Lelystad strain. For Cooperia oncophora and Nematodirus helvetianus no clear differences between locations were observed in the permanently grazed calves. No inhibition occurred in tracer calves turned out in August in either location, but differences were seen among tracer calves turned out in October. The Lelystad strains, kept in Lelystad or transferred to Utrecht, showed no inhibition, while in the tracer calves grazed on pastures contaminated by the Utrecht strains a marked inhibition of O. ostertagi and N. helvetianus was observed. The Lelystad strains appear to lack the ability, possessed by the Utrecht strains, to inhibit their development in autumn in response to environmental stimuli.
对来自荷兰两个不同地点的牛线虫菌株在发育受抑制倾向方面可能存在的差异进行了实地研究。在一个地点（莱利斯塔德），由于感染性幼虫受到环境刺激，这些菌株被认为缺乏发育受抑制的能力，而在另一个地点（乌得勒支），推测存在这种能力。莱利斯塔德的菌株留在原地，也被转移到乌得勒支的一个牧场，而乌得勒支的菌株仍留在乌得勒支。在这两个地点，所有长期放牧的犊牛体内奥斯特他加线虫早期第四阶段受抑制幼虫的比例都很高，乌得勒支菌株的比例高于当地和转移过来的莱利斯塔德菌株。对于库珀线虫和瑞士细颈线虫，在长期放牧的犊牛中未观察到地点之间的明显差异。8月在任何一个地点放出的示踪犊牛都没有出现发育受抑制的情况，但10月放出的示踪犊牛之间存在差异。留在莱利斯塔德或转移到乌得勒支的莱利斯塔德菌株没有出现发育受抑制的情况，而在放牧于受乌得勒支菌株污染牧场的示踪犊牛中，观察到奥斯特他加线虫和瑞士细颈线虫有明显的发育受抑制现象。莱利斯塔德菌株似乎缺乏乌得勒支菌株所具有的在秋季对环境刺激作出反应而抑制其发育的能力。
