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《中国蚕业》2016,(2)
家蚕微粒子病是由家蚕微孢子虫(Nosema bombycis)侵染引起的一种家蚕疾病,可经胚胎传染给子代,对蚕桑生产危害很大,是蚕种生产中唯一的检疫对象。根据浙江省30多年来家蚕一代杂交种母蛾微粒子病检疫数据分析,浙江省家蚕一代杂交种微粒子病发生情况及其一代杂交种的淘汰率和未检出率的相关性,进而从不同生产季节、不同品种方面分析了家蚕一代杂交种微粒子病发生情况,结果表明:家蚕一代杂交种的淘汰率(因母蛾微粒子病检疫不合格而淘汰蚕种的比例)和未检出率(母蛾微粒子病检疫时未检出微粒子孢子蚕种的比例)呈负相关,秋期生产的一代杂交种淘汰率较高,不同家蚕品种之间的淘汰率差异不大。建议根据浙江省近年来家蚕微粒子病发生的原因和趋势,制定有效的预防措施和控制方案,最大程度上降低家蚕微粒子病给蚕种生产带来的损失。 相似文献
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<正> 一、建国后家蚕微粒子病的防治工作家蚕微粒子病,是由家蚕微孢子虫经下传染和胚胎传染而寄生子蚕体内所造成的一食种传染性病害、该病对蚕桑生产影响极大,轻则降低养蚕收入,重则全部失收,并严重威胁着蚕种生产,是一种列为国家检疫对象的蚕病。解放前,江苏省家蚕微粒子病危害严重,使农村蚕茧生产受到很大损失。建国后,在政府领导下,成立了蚕种监管机构,强化了蚕种检验,实行全部袋蛾集中镜检,坚决淘汰超毒蚕种,不断提高合格毒率标准,并制定了防微措施,落到实处,杜绝传染途径。从而至1954年起江苏省实现了母蛾 相似文献
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家蚕微粒子病是一种危害性很强的蚕病。根据家蚕微粒子病具有胚种传染和食下传染两种传染方式特点,采用数理统计方法对检验数据进行详细分析研究,探索广西家蚕微粒子病发生原因和流行规律。结果显示,通过严格执行现行检疫技术标准,在蚕种生产中基本能控制家蚕微粒子病胚种传染危害。调查发现养蚕环境中微孢子虫污染严重,对应蚕生产蚕种的母蛾微粒子病发生率高,两者存在显著相关性,由此证明养蚕环境中微孢子虫污染严重造成的家蚕食下传染是家蚕微粒子病发生的重要原因;在蚕种生产中,气象因素对家蚕微粒子病发生也有影响。气温影响最为重要,降雨、日照起到辅助效果;建立两种基于蚕种微粒子病发生与环境微孢子虫分布关系以及与气象因子关系的数学模型,对家蚕微粒子病发生进行预测预报,为蚕种生产防控家蚕微粒子病提供依据。 相似文献
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家蚕微粒子病的化学治疗及应用研究进展 总被引：5，自引：0，他引：5
家蚕微粒子病是一种毁灭性的传染性蚕病,因能胚种传染,各产丝国家均将其列为蚕种制造的检疫对象。在防治措施上,采用镜检母蛾淘汰病卵以杜绝胚种传染,在原蚕饲养中则通过消毒防病来预防食下 相似文献
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加强防微工作 提高蚕种质量 总被引：1，自引：0，他引：1
<正>家蚕微粒子病是家蚕最主要的传染性疾病之一。它是典型的慢性疾病,具有病程周期长,传染途径广,为害性大,不易防治等特征,是一种严重为害蚕种生产的毁灭性蚕病。近年来,我站在母蛾检疫、成品检疫中检出微孢子的情况虽时有发生,但不合格种比率较低。尽 相似文献
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家蚕微粒子病是威胁蚕种生产最严重的传染性蚕病,从1996年至2004年,乐山市蚕种母蛾和成品微粒子病检疫检出不合格蚕种累计达75800余张,直接经济损失1516000余元。总结这些年的经验和教训,凡是桑叶全程消毒工作做得扎实的蚕种场,母蛾和成品微粒子病检疫的情况就非常好, 相似文献
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杂交种成品卵微粒子病检验技术的应用 总被引：1，自引：0，他引：1
1杂交种成品卵微粒子病检验在生产上应用的必要性
众所周知,家蚕微粒子病是一种传播快危害大的毁灭性病疫,被世界各国列为检疫对象.微粒子病的传播途径有两种,一是食下传染,二是胚种传染.控制食下传染主要是严格贯彻消毒防病措施,而控制胚种传染的有效途径仍然是采用100多年前法国巴斯德创立的母蛾镜检法.但是,母蛾检验结果的真实性和可靠性是以抽样袋蛾和样本处理是否标准来决定的,在多年的检验实践中也证实了这一点.因此,为了防止母蛾检验中可能发生的一些问题,弥补之不足,从根本上杜绝胚种传染,有必要在母蛾检验的基础上,对一代杂交种成品卵进一步作微粒子病检疫,为严禁超毒种发放,保证蚕作安全做最后的把关. 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献