Study on the inductive factors of hypobiosis of Ostertagia ostertagi in cattle
Study on the inductive factors of hypobiosis of Ostertagia ostertagi in cattle
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DOI：
10.1016/s0304-4017(98)00252-0
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发表时间：
1999-03-15
影响因子：
2.6
通讯作者：
Steffan, PE
中科院分区：
文献类型：
--
作者：
Fernández, AS;Fiel, CA;Steffan, PE
本文通过两个试验，探讨了引起牛奥斯特线虫（Ostertagia ostertagi）共生现象的原因。在第一个实验中，在2年的时间内研究了时间对环境中第三阶段幼虫的影响。三个被O.使用一年中不同时间的奥斯特线虫卵，并通过使用“指示”和“示踪”小牛记录低生态水平。结果表明，时间本身不是一个hypobiosis-inductive因素。第二个试验在实验室条件下进行，研究了温度和光照对感染性幼虫的影响。感染幼虫在6周内经历不同的温度和光照条件，然后接种到寄生虫未感染的小牛，4周后屠宰。根据接种前幼虫所经历的不同储存条件，这些小牛中的低生物性幼虫的存活率从3.5%到94.8%不等。结果表明，温度升高和光照时间增加模拟春季条件下将是作用于第三阶段的幼虫诱导他们在宿主中的一个较晚的低生阶段的因素。(C)1999 Elsevier Science B. V.保留所有权利。
Two experiments were carried out to determine the causes producing the Ostertagia ostertagi hypobiosis phenomenon in cattle. In the first experiment, the effect of time on third-stage larvae in the environment was studied during a 2-year period. Three experimental paddocks contaminated with O. ostertagi eggs at different times of the year were used, and the levels of hypobiosis were recorded by using 'indicator' and 'tracer' calves. The results suggest that time as such is not a hypobiosis-inductive factor. The second experiment was conducted under laboratory conditions, where the effects of temperature and light on infective larvae were studied. Infective larvae were subjected to different conditions of temperature and light during 6 weeks, and then inoculated to parasite-naive calves, which were slaughtered after 4 weeks. Percentages of hypobiotic larvae in these calves varied from 3.5 to 94.8%, depending on the different storage conditions the larvae underwent before inoculation. Results suggest that increasing temperature and increasing time of light exposure simulating spring conditions would be the factors which act upon third-stage larvae inducing them to a later hypobiotic stage in the host. (C) 1999 Elsevier Science B.V. All rights reserved.