鸡传染性法氏囊病流行病学及其防控措施

<正>鸡传染性法氏囊(IBD)是一种主要危害雏鸡的免疫抑制性及高度接触性传染性疫病,发病率高,病程短,影响大,可诱发多种疾病或使多种疫苗免疫失败,是危害养鸡业传染病之一。近年来,鸡传染性法氏囊病在全国呈上升趋势,出现新的特点。免疫抑制和生长抑制是该病的最大特点。抗原变异株和超强毒株出现,使该病的防治面临新困扰,尤其超强毒株(毒力变异株)引起高达60%~100%的死亡率,因此,该病今年来被形象地称为     

传染性法氏囊病的症状与防制

一病原 传染性法氏囊病是一种重要的家禽免疫抑制性疾病，死亡率为5％～70％。已经证实，我国不仅存在类似于欧洲的超强毒株，也存在类似于美国的变异株。这使得我们在该病的疫苗防治上必须选择与变异株有着较高交叉保护率的毒株。     

鸡传染性法氏囊病病毒VP2蛋白研究进展

鸡传染性法氏囊病（Infectious bursal disease,IBD）是由鸡传染性法氏囊病病毒（Infectious bursal disease virus,IBDV）引起的一种急性、高度接触性传染病,主要危害3～6周龄的雏鸡。该病于1957年首次发现于美国Gumboro地区。50年来,IBD一直威胁着养禽业的发展。免疫抑制、抗原变异,特别是超强毒株（vvIBDV）的出现,使得该病的防控形势更加严峻。国际兽疫局（OIE）已将IBD列为“影响社会经济的重要疾病”。     

新技术防治传染性法氏囊病的研究进展和思考

传染性法氏囊病 ( IBD)自 1 96 2年被确认以来 ,已成为世界养禽业最严重的传染病之一。该病的经济重要性主要表现在 :1雏鸡感染本病后导致严重的长期免疫抑制 ,使鸡群对其他重要疫病 ,如传染性支气管炎、新城疫、马立克氏病的免疫失败 ;2该病病原传染性法氏囊病病毒 ( IBDV)的某些毒株能使 3周龄以上的鸡发病 ,其死亡率最高可达 1 0 0 % ,1 998年因 IBD引起的禽死亡率仍居各种禽病首位 [1 ] ;3IBDV变异株和超强毒株的出现 ,经常使 IBD本身免疫失败。IBDV自身的特点也使其成为许多学者特别是非动物医学界人士感兴趣的“模式病毒”,…     

传染性法氏囊病及其防控

传染性法氏囊病(IBD)是由传染性法氏囊病病毒(IBDV)引起的以侵害雏鸡淋巴组织尤其是中枢免疫器官——法氏囊为主要特征的一种急性、高度接触性传染病。该病不仅可破坏B淋巴细胞的结构,同时还会导致胸腺和脾脏的淋巴组织坏死,引起机体免疫抑制,导致免疫失败。免疫抑制、抗原变异、特别是超强毒株的出现(vv IBDV),使得该病的防控形势更加严峻。     

鸡传染性法氏囊病的流行特点与防控

鸡传染性法氏囊病(IBD)是由双RNA病毒科双RNA病毒属的传染性法氏囊病毒(IBDV)引起的一种急性、高度接触性传染病.自该病传入我国以来,就一直严重危害着我国的养禽业发展,尤其是变异株和超强毒株的出现,给该病的防制带来了困难,尽管我国采取了控制与扑灭IBD的措施,但由于目前养禽业管理的不规范化和污染源的存在,IBD迄今仍然是威胁养鸡业的头号传染病之一.     

传染性法氏囊病病毒变异的分子基础

鸡传染性法氏囊病病毒(IBDV)是传染性法氏囊病(IBD)的病原体。由于急性感染的高死亡率和亚临床感染严重的免疫抑制,IBDV对养禽业经济上有重大的影响[11,14]。IBDV共有两个血清型,即1型和2型,血清1型对鸡有致病性,血清2型分离自火鸡,对鸡无致病性。J.Rosenberger(1985)首次从美国特拉华半岛肉鸡群分离到4株IBDV变异株,1987年,荷兰、比利时爆发了与美国株不同的超强病毒(vvIBDV)。而后,英国、法国、西班牙、德国等欧洲国家相继分离到超强毒株。李树根(1991)等首次在国内分离到血清亚型株,李德山(1991)首次报道了中国超强毒株,朱爱国…     

前鸡传染病流行的新特点、成因及对策

同一疾病临床症状呈现多种类型同时并存，且各临床症状间相关性很小，自然康复后的交叉保护率很低。如传染性支气管炎有传统的呼吸道型、产蛋下降型、嗜肾型、嗜肠道型、嗜腺胃型以及尚未定论的可以造成肌肉损伤的等。已分离出的毒株达30余种，血清型众多；传染性法氏囊病(IBD)在临床上也出现了法氏囊感染两天即迅速萎缩，并导致严重免疫抑制的变异株形成的IBD，又有能突破高水平母源抗体导致1周龄雏鸡感染发病的超强毒株引起的IBD，表现为从1周龄到开产鸡都能发病的临床特点；马立克氏病(MD)则有神经损伤型、皮肤型、内脏型、眼型等多种，既有温和的亚临床感染导致免疫抑制，又有造成巨大损失的超强毒株引起的爆发等。     

白羽肉鸡传染性法氏囊疾病防控

<正>鸡传染性法氏囊病(infectious Bursal Disease,IBD)是由呼肠弧病毒引起的一种急形、高度传染性疾病。由于该病发病突然、病程短、死亡率高,且可引起鸡体免疫抑制,目前仍然是白羽肉鸡主要传染病之一。1鸡传染性法氏囊病的病原学及临床症状IBDV有两个血清型,鸡源性病毒为血清I型,能引起鸡发病;血清II型毒株来源于火鸡,对鸡和火鸡都无致病力。IBD出现的初期是以经典毒株     

IBD引起家禽免疫抑制的作用机理及其防制

IBD是一种可引起家禽免疫抑制的病毒性疾病,一直是养禽业非常重视的最重要的传染性疾病之一,近年来由于其超强毒株(vvIBDV)的出现,更受关注。本文综述了IBD的概念特征、免疫抑制机理及表现,并提出综合防制策略。     

商会自治的基石——商会自治规范研究

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。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

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。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

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.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

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。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

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。     

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.