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禽大肠杆菌病是由致病性大肠杆菌引起的禽类多种病型的总称。它常继发于其他致病因子或与其它致病因子一同作用,病理表现复杂多变,往往使真正的罪魁祸首得以掩盖。禽大肠杆菌病发病频繁,易反复发作,加之用药较乱,病原菌血清型多、抗原结构复杂,极易产生耐药性且防不胜防。特别是商品肉仔鸡的饲养,该病已成为制约养鸡业发展的主要禽病之一。1禽大肠杆菌病的症状与病变分类由于病禽的年龄、抵抗力、病原菌毒力、感染途径等不同,其症状、病变亦不同。常表现为大肠杆菌败血症、腹膜炎、输卵管炎、气囊炎、全眼球炎、大肠杆菌性肉芽肿、禽蜂窝织… 相似文献
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水禽大肠杆菌病病原的分离与血清型鉴定 总被引：1，自引：0，他引：1
《养禽与禽病防治》2007,(11)
禽大肠杆菌病是由多种致病血清型或条件致病性大肠杆菌引起的不同类型禽病的总称。随着饲养数量与密度的不断增大,水禽大肠杆菌病已成为常发病之一,同时经常出现使用抗菌药物防治及免 相似文献
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<正>大肠杆菌病是家禽养殖场的顽疾之一,对春季产蛋母鹅的危害尤为突出,常出现成批死亡现象,死亡率高达10%。如何防治大肠杆菌病已经成为养鹅业主的一块心病。本文针对鹅大肠杆菌病的防治做一简单叙述。大肠杆菌病是有不同血清型埃希氏大肠杆菌所引起的一种传染病。当鹅感染大肠杆菌后,由于其日龄、感染途径不同及大肠杆菌致病力的不同,可以产生许多症状和病变不同的病型。15日龄以内的雏鹅呈急性败血症,由于致病性埃希 相似文献
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禽大肠杆菌病是由多种血清型的致病性大肠杆菌所引起的不同类型禽病的总称。大肠杆菌是健康畜禽肠道中的常在菌，可分为致病性和非致病性两大类。由于其抗原性复杂血清型多样，临床病变复杂，且常与病毒性疾病和其他细菌性疾病并发或继发，给养鸡业带来相当大的危害，该病的防治尤为重要，药物防治仍是目前采用的主要方法，但由于用药不当或药物滥用，加速了细菌耐药性的产生。此项试验选择氟苯尼考、硫酸安普霉素、硫酸阿米卡星等20种单一药物，进行药敏试验，旨在选择对大肠杆菌无耐药性或耐药性低的药物，为大肠杆菌病的药物防治提供理论依据。 相似文献
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《黑龙江畜牧兽医》2017,(15)
近年来,由禽致病性大肠杆菌(avian pathogenic Escherichia coli,APEC)引起的禽大肠杆菌病给全球的养禽行业造成了重大的经济损失,并且APEC引起的禽大肠杆菌病在中国是最主要的家禽细菌病。越来越多的证据显示,APEC是人源尿路感染大肠杆菌(uropathogenic Escherichia coli,UPEC)和致脑膜炎大肠杆菌(neonatal meningitis Escherichia coli,NMEC)的毒力基因储藏库,甚至可能会直接导致两种疾病的发生。因此,如何有效地控制APEC不仅是一个紧迫的问题,更是一个巨大的挑战。对APEC的分离鉴定、流行病学特征、药物敏感性等内容的研究对APEC引起的禽大肠杆菌病的控制具有指导意义。为了更好地防控大肠杆菌病,文章主要从临床症状、病理变化、毒力因子、致病机理和诊断方法几个方面对鸭致病性大肠杆菌进行了综述,以期为进一步研究提供参考。 相似文献
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大肠杆菌致病因子研究进展 总被引：2，自引：1，他引：1
禽致病性大肠杆菌和尿道致病性大肠杆菌是引起禽类和人肠道外感染的主要病原菌,这两种病原菌的毒力因子,致病机理及其相关性的研究现已成为热点。本文对近年来这些方面的研究进展进行概述。 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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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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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
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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
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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