Sanyal P K, Sarkar A K, Patel N K, Mandal S C, Pal S
Department of Parasitology, College of Veterinary Science and Animal Husbandry, Indira Gandhi Krishi Viswavidyalaya, Anjora, Durg-491 001, Chhattisgarh, India.
J Helminthol. 2008 Jun;82(2):169-74. doi: 10.1017/S0022149X08936531. Epub 2008 Mar 10.
Experiments on the influence of egg density and varying quantities of chlamydospores on the nematode-trapping ability of Duddingtonia flagrans, influence of D. flagrans on the larval translation of gastrointestinal nematodes, doses of chlamydospores required for the effective control of gastrointestinal nematodosis and the epidemiology of nematode parasites were conducted in goats, which generated baseline data required for strategic application of the biocontrol agent. The nematode-trapping ability of D. flagrans, measured by numerical enumeration of infective third-stage larvae developed in the faecal culture, revealed that the efficacy is dependent on both nematode egg and chlamydospore density. Pasture plot studies revealed that D. flagrans, if deposited at the same time as nematode eggs, prevents translation of third-stage larvae of caprine nematodes from the faecal pats onto the grass blades. Feeding of 1 x 106 chlamydospores per kg body weight and above to goats virtually eliminated larvae from the pasture. Application of as few as 1 x 104 and 1 x 105 chlamydospores per kg body weight had a profound impact on larval recovery. The effect persisted as long as the chlamydospores were fed. Monthly faecal worm egg counts of adult goats maintained under a semi-intensive management system on the Chhattisgarh plain and pasture larval burden revealed that June to August were the months of high risk for nematodosis. Haemonchus was the dominant species recorded throughout the year. The present data can best be utilized by formulating a strategic control measure when the larval challenge to the animal is maximum (June to August), so as to prevent establishment of patent infection. The observations reinforced the strategy to be adopted for nematode parasite control in goats by applying the biocontrol option at the onset of the monsoon.
开展了关于卵密度和不同数量厚垣孢子对弗氏节丛孢线虫捕捉能力的影响、弗氏节丛孢对胃肠道线虫幼虫迁移的影响、有效控制胃肠道线虫病所需的厚垣孢子剂量以及线虫寄生虫流行病学的实验，这些实验以山羊为对象，生成了生物防治剂战略应用所需的基线数据。通过对粪便培养物中发育的感染性第三期幼虫进行数值计数来衡量弗氏节丛孢的线虫捕捉能力，结果表明其功效取决于线虫卵和厚垣孢子的密度。牧场小区研究表明，如果弗氏节丛孢与线虫卵同时投放，可防止山羊线虫的第三期幼虫从粪便团转移到草叶上。每千克体重给山羊投喂1×10⁶及以上数量的厚垣孢子，几乎可使牧场中的幼虫消失。每千克体重投喂低至1×10⁴和1×10⁵个厚垣孢子对幼虫回收率也有显著影响。只要持续投喂厚垣孢子，这种效果就会持续。对恰蒂斯加尔平原半集约化管理系统下成年山羊的月度粪便虫卵计数以及牧场幼虫负荷显示，6月至8月是线虫病的高风险月份。全年记录到的优势种为血矛线虫。当动物面临的幼虫挑战最大时（6月至8月），制定战略控制措施以防止显性感染的建立，就能最好地利用目前的数据。这些观察结果强化了在季风开始时应用生物防治方法来控制山羊线虫寄生虫的策略。
