非典型鸡新城疫的诊断与防制体会

近年来 ,由于疫苗使用不当 ,环境污染严重 ,应激因素及免疫抑制性疾病的干扰等 ,致使鸡群的免疫力不够坚强。受到强毒感染后经常发生非典型鸡新城疫 ,且常并发或继发大肠杆菌病或霉形体病等。同时又易于和禽流感、传染性支气管炎、减蛋综合征等相混淆 ,给养鸡业造成了严重的损失。1　发病特点非典型新城疫主要发生于经新城疫疫苗免疫过的鸡群 ,以经 2～ 3次疫苗免疫的鸡群较多。发病后不表现明显的临床症状和剖检病变 ,死亡率很低 ,一般在 5 %以下。病程长 ,可达2～ 3周 ,有的长达 1～ 2个月。不同品种和年龄的鸡均可发生 ,以产蛋鸡多发。雏…     

鸡新城疫的诊治及防制措施

新城疫（Newcastle Disease,ND）,是由副粘病毒科副粘病毒亚科腮腺炎病毒属的禽副粘病毒Ⅰ型引起的高度接触性禽类烈性传染病。世界动物卫生组织（OIE）将其列为必须报告的动物疫病,我国将其列为一类动物疫病。新城疫是危害鸡的主要疫病之一,同时感染其他病原菌如大肠杆菌引起的内源性感染,将会使产蛋鸡产蛋量下降,育成鸡死亡率增加。现结合我县多巴种鸡场育成蛋鸡新城疫并发大肠杆菌病的诊治情况,谈一下蛋鸡新城疫的防治措施。     

青年鸡新城疫的诊疗

一饮水免疫饮水免疫是养鸡生产上常用的一种主动免疫办法，省时高效，应激小。在规模化养殖而不便于滴鼻点眼的情况下，多采用此法。但是饮水免疫受水质、     

鸡新城疫的综合防制

虽然我国依靠疫苗对鸡新城疫（ND）取得了较好的控制，但该病至今仍是危害我国养鸡生产的重要疫病之一，每年造成的经济损失也是很大的。在实际生产中新城疫仍是养鸡业的一种常见病和多发病，特别是非典型新城疫。本文对目前我国鸡新城疫的发生与流行特点和防制措施作一简述，以供养鸡生产中防制该病参考。１鸡新城疫的发生与流行特点１．１非典型新城疫是养鸡生产中的主要表现形式我国对该病的防制十分重视，鸡群普遍采用疫苗免疫接种，对该病的控制起到了很好的作用。因此在实际生产中如教科书中描述的典型的新城疫并不多见，而是以非典…     

鸡群新城疫监控的几个重要环节

新城疫(ND)又称亚洲鸡瘟或伪鸡瘟,是由副粘病毒科的新城疫病毒(NDV)引起的一种主要侵害鸡的高度接触传染性致死性疾病,被我国农业部列为一类烈性传染病。由于多数饲养鸡群都采取了新城疫预防接种和综合防疫相结合的措施,已大大减少了本病危害。但是近些年,由于饲养规模越来越大,禽及其产品贸易往来更加频繁,防疫和用药方式不太合理,使得过去那种最急性和急性的新城疫病例已经较少见到,而比较多见的是免疫鸡群的非典型新城疫的发生。在我国的规模化饲养和散养并存的复杂饲养条件下,如何控制好鸡新城疫已成为直接影响养鸡业发展的重要因素之…     

鸽新城疫病毒在鸡胚上的增殖动态

采用红细胞凝集试验（HA），通过对鸽新城疫病毒（NDV）在鸡胚上增殖动态的研究表明，ND－gs01病毒经尿囊腔接种9－10日龄鸡胚、24h内病毒处于“掩蔽期”，24h后开始增殖，72h左右鸡胚死亡。新城疫病毒在尿囊膜、羊膜、尿囊液、羊水中含量较高，增殖动态趋于一致。卵黄、胚体中含量较低。上述结果，为该病毒的进一步研究和应用提供了科学依据。     

鸡非典型新城疫研究进展

鸡新城疫 (ＮｅｗｃａｓｔｌｅＤｉｓｅａｓｅ)是危害养鸡业的主要鸡病之一。 2 0世纪 80年代末 ,该病的发生出现了新的变化 :多发生于有母源抗体的雏鸡和免疫鸡群 ;临床症状不典型 ;发病季节不明显 ;发病鸡有较高的抗体水平。因此容易被忽视和引起误诊而造成较大的经济损失。本文就鸡非典型新城疫的流行、发病原因、临床症状、病理变化、诊断及防制措施作一简述。1　流行病学特点宿主范围不断扩大。最初报道的宿主是鸡和火鸡 ,近年来在鹦鹉、鹌鹑、鸽体内分离到病毒 ,在鸭、鹅等水禽体内也分离到了病毒。因此 ,该病的感染范围有扩大趋势 ,…     

鸡非典型新城疫的诊断及防制方法

鸡新城疫是一种急性烈性传染病。常呈区域性、大范围的流行,传播非常迅速,造成重大的经济损失,严重威胁着养鸡业的发展。近年来,由于各鸡场都十分重视该病的免疫接种.因此,典型的、急性的新城疫已被基本控制。然而在一些鸡场中却出现了非典型、慢性的新城疫。非典型性鸡新城疫是一种临床表现为死亡率相对较低,多数感染鸡群精神沉郁、食欲不振、羽毛蓬松、呆立少动,急、慢性腹泻,生长发育迟缓,产蛋鸡还表现为产蛋率急剧下降,蛋壳质量下降,畸型蛋、破损蛋明显增加。这一变化往往导致将本病误诊为其他传染病如呼吸道疾病等,而贻误了本病的防治时机,给鸡场带来不应有的损失。     

Exotic Newcastle disease in a game chicken flock.

A sudden increase in mortality, preceded by a short history of respiratory signs and diarrhea, occurred in a backyard flock of 48 game chickens in the Central Valley of California. Necropsy findings included severe generalized linear hemorrhages and/or ulcers in the digestive tract, larynx, and trachea. Histology revealed severe multifocal hemorrhages and necrosis in the mucosa of the respiratory and digestive tracts, vasculitis, and necrosis of lymphoid tissue. The birds were serologically negative to Newcastle disease virus; this was consistent with an acute infection. The avian paramyxovirus type 1 isolated was characterized as velogenic viscerotropic Newcastle disease virus. A thorough epidemiologic investigation was carried out, and no other premises were found to have birds with clinical signs or evidence of exposure. The entire outbreak was limited to the original backyard flock and resolved within 14 days of the onset of clinical signs.     

鸡新城疫（ND）各种免疫程序的测定

本试验进行了三批鸡的免疫研究。第一批试验检测不同类型新城疫疫苗在不同母源抗体水平（高和低）的鸡体上的免疫效果。结果显示,在高母源抗体时免疫,Ｖ４组和油乳剂灭活苗级抗体水平表现较低,而在低母源抗体时免疫,几种疫苗的抗体水平上升得很快,特别Ｌａｓｏｔａ－克隆３０组最明显,而油乳剂灭活苗组的抗体水平保持最长。根据此结果而制定了不同的免疫程序,进行了第二、第三批免疫试验,并分别在４５天龄及７０天龄时进行强     

老鸡场新城疫发生的形式及防治对策

新城疫是每一个鸡场都必须控制的疾病,但近年来在一些老鸡场虽已控制多年却仍时有发生,有的甚至呈暴发性流行。有的商品肉鸡场遭遇一次大流行可导致10多万只乃至几十万只的鸡群全军覆没,在这些鸡场,许多常规的防治措施及多年来行之有效的制度形同虚设,损失之惨重令人触目惊心,由此造成的严重后果令人痛惜。笔者对郊区10多个鸡场近年来新城疫发生流行的情况进行了调查和分析。1发生形式1.1非典型性发病该类型在一半以上的老鸡场都有不同程度的发生。以轻度呼吸道症状为主,一部分鸡伴有轻度拉稀,鸡群中有零星的延续性死亡;商品肉鸡常发育不良,…     

车前草多糖对雏鸡新城疫疫苗免疫效果的影响

为研究车前草多糖对雏鸡新城疫疫苗免疫效果的影响,将350只雏鸡随机分为7组,于8日龄、22日龄进行新城疫疫苗首免和二免,同时给予车前草多糖,并以黄芪多糖和铝胶盐佐剂作为对照,分别在首免后第7、14天,二免后第7、14、21天进行血清抗体效价和淋巴细胞增殖率的测定,于二免后第21天用新城疫病毒进行攻毒,连续观察10d内鸡的发病及死亡情况。结果显示,车前草多糖能显著提高雏鸡新城疫疫苗的免疫抗体效价、增强雏鸡的淋巴细胞增值率,与黄芪多糖的作用无显著性差异(P0.05),但车前草多糖提高抗体效价作用较黄芪多糖、铝胶盐佐剂的维持时间长;在新城疫病毒攻毒后10 d,未免疫组雏鸡全部死亡,车前草多糖高、中剂量组的攻毒保护率为100%,车前草多糖低剂量和黄芪多糖的保护率为90%,而铝胶佐剂和ND疫苗免疫组的保护率仅为70%。试验结果表明,车前草多糖能提高新城疫疫苗的抗体效价水平和增强T淋巴细胞的增殖率。     

中药防治鸡新城疫研究进展

鸡新城疫又称亚洲鸡瘟,是由鸡新城疫病毒引起的鸡的一种高度接触性、急性、烈性传染病。常呈现败血症经过,主要特征是呼吸困难、下痢、神经机能紊乱、黏膜和浆膜出血等。     

A reservoir of virulent Newcastle disease virus in village chicken flocks

Village chicken flocks in 6 different regions of Morocco were studied for the presence of Newcastle disease. Three of the regions contained industrialised poultry farming and 3 were isolated mountainous regions with no industrialised poultry farming. Serum samples and tracheal swabs were taken from 100 chickens in each region. Antibodies against Newcastle disease virus (NDV) were found in chickens from every region. Forty-one isolates of NDV were obtained including some from chickens in every region. Two virus isolates from each region characterised and all were found to be velogenic. Thus, village chicken flocks throughout Morocco harbour a reservoir of virulent NDV, independently of industrialised farms.     

农村狂犬病防控工作中的问题及措施

近年来,农村养犬数量不断攀升,“管、免、灭、宣”措施难落实,工作机制不健全,人们对狂犬病防控意识不强等,是导致农村狂犬病防控工作不到位的主要原因,致使狂犬病疫情呈抬头趋势。     

不同佐剂对鸡新城疫疫苗免疫调节作用的影响

试验以300只AA雏鸡为试验动物,将其随机分为4组,A、B、C组分别接种相同剂量的甲壳素、蜂胶、铝胶佐剂苗,D组为对照组。结果表明,三种佐剂的疫苗在对肉鸡组免疫的第3、4、5、6、7、9、11、13、15、20、25天后,甲壳素疫苗组H I抗体效价显著高于其它组,蜂胶疫苗组H I抗体效价其次,铝胶疫苗组抗体H I效价最低;用三种不同佐剂的疫苗对肉鸡免疫后第26天称其重量,甲壳素佐剂疫苗组免疫后的肉鸡增重效果最好,蜂胶疫苗组居中,铝胶疫苗组最差。     

Characterization of Newcastle disease viruses isolated from chicken,gamefowl, pigeon and quail in Mexico

Velogenic Newcastle disease has threatened the Mexican poultry industry since 1946. Seven strains of velogenic Newcastle disease virus were isolated from poultry and other avian species in central and northern Mexico from 1998 to 2006 and subjected to phylogenetic analysis and biological characterization using standard pathogenicity tests and challenge studies. Phylogenetic analysis showed that all velogenic strains belonged to genetic group V and are clearly divided in two lineages, since phylogenetic similarities between groups are of only 93–94%. Isolates from 1998 to 2001 are closely related to the strain responsible for the 2000 year outbreak raised in La Laguna region (Torreon strain), and are phylogenetically distinct from viruses isolated between 2004 and 2006 that are genetically related to the Chimalhuacan strain isolated in 1973. All the viruses of both, the Chimalhuacan and the Torreon groups, contained a virulent fusion protein cleavage site represented by the motif “GGRRQKRF”, revealing that evolutionary changes occurred at a different site. Chicken embryo mean death time value was shorter for the Chimalhuacan-like viruses (43.9 hours), when compared with the 1998–2001 average (54.3 hours). ICPI average value was higher (1.92) for viruses isolated during 2004–2006 than that for viruses isolated before 2001 (1.74). Microscopic evaluation of bursa of Fabricius and thymus of 5w-o broiler chickens challenged with 10⁶ LD₅₀/0.2 ml showed that Chimalhuacan-like isolate caused more severe lesions at 48 hpi in bursa and 72 and 96 hpi in thymus than Torreon-like isolate. Along with the MDT, ICPI and microscopic results, our findings suggest that some distinct selective pressure on the very virulent Chimalhuacan strain isolated in early 1970’s may have led to the appearance of the still velogenic but less virulent new group (Torreon-like) in the middle of 1990’s.     

鸵鸟新城疫的诊断及防制

新城疫 (Newcastle Disease,ND)是禽类的一种高度接触性致死性传染病 ,以鸡和火鸡最易感。但是 ,近年来随着鸵鸟养殖业的发展 ,鸵鸟 ND在世界各国都有不同程度的发生。 2 0 0 0年 2月 ,某鸵鸟养殖场暴发 ND,在 5天之内 ,2 4只体重为 10 0 kg左右的未成年鸵鸟死亡 10只 ,死亡率 4 4%。两年来经用卵黄抗体、中药及环境消毒等措施综合防制 ,未见再发病。1　发病情况　 2 0 0 0年 2月初 ,气温骤降 ,室外盖上厚厚的积雪。 2月 4日有几只鸵鸟出现精神委顿 ,食欲降低 ,拉稀 ,翅膀下垂 ,呼吸加快。次日凌晨死亡 1只 ,另有 2只不能站立 ,卧于舍内…     

Vaccination with Newcastle disease vaccine and CpG oligodeoxynucleotides induces specific immunity and protection against Newcastle disease virus in SPF chicken

Oligodeoxynucleotides containing unmethylated CpG motifs (CpG ODN) have been proven to be immunoprotective in mouse models. However, little work has been conducted on in vivo immune responses in chicken with CpG ODN. The objective of this study was to investigate the immunoadjuvant effects of CpG ODN to Newcastle disease (ND) vaccine and its protective effects against ND virus in SPF chicken. In this report, the titre of serum IgG to ND vaccine and the proliferation of lymphocytes were monitored in SPF chickens. The results demonstrated that the above-mentioned immune responses were significantly stronger in chickens that received CpG ODN than in the birds that received only ND vaccine. Furthermore, ND vaccine plus CpG ODN protected SPF chicken from challenge with an otherwise lethal dose of ND virus. These data suggest that CpG ODN holds considerable promise as an adjuvant for future vaccines against ND virus.