幼年牦牛寄生线虫吸虫动态及防治的研究

STUDIES OF DYNAMICS AND CONTROL OF NEMATODES AND TREMATODES IN YOUNG YAKS

在青藏高原东部地区,通过调查寄生虫病对草原牦牛饲养业的危害,病原分类,流行规律及防治对策等一系列研究,探明寄生虫病是引起幼年牦牛春乏死亡的重要原因;在已查明青海牦牛的85种寄生虫中,优势虫种有17～22种。对线虫寄生阶段幼虫和成虫自然消长规律同步研究结果证明,冬季的幼虫寄生高潮是形成春季成虫高潮的主要来源;春季成虫高潮与牦牛春乏死亡密切相关;冬季适时驱杀占优势的线虫受阻型幼虫和其它蠕虫,能够有效地预防春季成虫高潮的出现;1～2月应用丙硫咪唑按10～20mg/kg体重剂量,对幼年牦牛进行一次口服投药驱虫,经对10万余头牛示范推广应用观察,可使春乏死亡率下降幅度达71.6％～93.3％,每头牛平均多增或少减活重2.3～5.05kg。本项研究与笔者等对羊线虫的研究结果吻合,从而阐明了寄生虫病春季高潮来由这一重大理论问题。在此基础上研究成功的冬季驱虫防治措施,方法简便易行,经济效益、社会效益显著。坚持推广该项技术,将为草原畜牧业生产带来可观的效益。

In eastern Qinghai-Tibet Plateau,by investigating parasitic harmfulness to yak feeding industry in grassland,pathogenic classification,epidemiology and control,we have known that certain parasitoses were the important cause of leading to spring weak/death of young yaks. Of 85 known parasites in the Qinghai yak,there were 17-22 dominant species. By synchronous studies on natural growth and decline laws of nematode parasitic stage larva and adult,the results showed that winter larva parasitic high tide was the origin of coming spring adult parasitic high tide;spring adult parasitic high tide is closely related to yak spring weak/death; driving out nematode larva of predominant developmentblocked type and helminth timely in winter can effectively prevent high tide appearance of adult worm in spring. Orally giving young yak albendazole(10-20mg/kg) in January or February, tested through over 100000 yaks, can lower spring weak/death rate 71.6%-93.3%,the average increased or less-reduced weight per yak was 2.3-5.05kg. These results coincide with our studies on sheep nematodes. Therefore we have expounded the important theory,i. e. why spring high tide of parasism would present. The winter control method based on our studies is handy and easily put into effect,and has remarkable economic and social benefits.