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牛海绵状脑病 (BSE)俗称“疯牛病” ,是传染性海绵状脑病的一种。是一种特殊病毒———朊病毒引起人和动物的一组具有共同特征的非炎性、亚急性、渐进性、致死性中枢神经系统变性的疾病 ,故又称朊病毒病。自从 2 0世纪 80年代英国出现疯牛病以来 ,已在欧洲一些国家扩大流行 ,引起世界各国的恐慌和关注。我国虽未发现疯牛病 ,但为了预防疯牛病的发生 ,笔者将有关知识简述如下。1 疯牛病的病因是由有传染性海绵状脑病的一种即绵羊、山羊痒病病羊的骨、肉被加工成粉 ,作为牛的饲料添加剂进入牛的饲料中 ,这种痒病羊的骨肉粉中间含一种特殊… 相似文献
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牛海绵状脑病(Bovine Spongiform Encephalopathy,BSE)又称疯牛病(Mad Cow Disease),是牛的一种神经性、渐进性、致死性疾病。1985年它首先在英国暴发,并迅速传播到欧洲多个国家和地区,给英国和欧洲的养牛业及相关产业造成了巨大损失。另外一种传染性海绵状脑病发生于羊,会引起羊痒病,造成羊永久性的脑部损伤,使脑组织形成海绵状空洞,导致精神错乱、痴呆、最终死亡,也具有非常大的危害。目前认为此类疾病主要是通过污染了朊病毒的牛肉、羊肉、脑、脊髓、扁桃体、胸腺、脾脏、小肠及其制品而传播发病,因此许多国家都已经禁止将牛、羊源性… 相似文献
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牛海绵状脑病(疯牛病)概述 总被引:1,自引:0,他引:1
牛海绵状脑病(疯牛病)概述李康然广西农业大学530005最近一段时期,英国的“疯牛病”引起英国及整个欧洲的恐慌,欧洲各国已断然拒绝了英国牛肉、活牛及奶制品的进口。英国政府迫于巨大的压力,不得不同意屠杀烧掉约400万头牛,牛龄超过30月龄的牛都可能带有... 相似文献
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近年来,英国疯牛病对人的威胁已成为国内外新闻媒介关注的焦点,它给英国养牛业造成了数百亿美元的直接经济损失。同时也引起了世界各国政府及农业主管部门的高度重视,并都采取了相应的应急措施。本文就近年来关于疯牛病及相关的羊痒病和克一雅二氏病的研究成果概述如下。一、病原学特性1.疯牛病是牛海绵样脑病(BSE)的俗称,本病首次报道于1985年年底。BSE的病原学尚不清楚,但对其的研究结果有不同报道。有人认为是由疯牛病病毒引起的,有人认为是由痒病病毒引起的,也有人认为是由一种牛适应型痒病病毒株引起的。有文报道本病病原… 相似文献
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牛海绵状脑病(疯牛病)徐兰芳,李通瑞(江西省家畜兽医防疫检疫站)(中华人民共和国动植物检疫总所)牛海绵状脑病(BovineSpongifromEncephalophathy,简称BSE)俗称“疯牛病”。是当前严重威胁养牛业的一种进行性、致死性、神经性... 相似文献
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牛海绵状脑病是国外最近几年新发现的一种疾病,又称疯牛病。本病是以脑灰质发生海绵状或海绵样变化为特征的,中枢神经系统变性的慢性疾病。该病潜伏期长,死亡率高。迄今已知,自然界的传染性海绵状脑病不仅存在于绵羊、山羊、鹿及人,还发生于野生反刍动物。最近查明,在英国牛群中已发现有“痒病样疾病”并称之为牛海绵状脑病(Bovine SpongiformEncephalopathy.BSE)。为提供一些准确判定此病的理论依据,防止本病侵入我国,特将近几年国外对 BSE 的研究情况概述如下。 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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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献