山东省鸡传染性贫血流行病学调查

本文对山东省12个地市58个鸡群传染性贫血的流行情况进行了调查，共检测了368份务清样品，蛋鸡群、肉鸡群和种鸡群的鸡传染性贫血病毒（CAV）ELISA抗体检出率分别为91．7％、77．6％和84．78％，平均抗体阳性率为83．2％，结果表明近几年山东省鸡群中CAV感染相当普遍，而且蛋鸡和种鸡CAV抗体阳性率明显高于肉鸡群。     

江西省主要养鸡地区鸡传染性贫血病的血清学调查

为了研究江西省鸡传染性贫血的流行情况,对江西省11个地市主要养鸡地区的24个鸡群中鸡传染性贫血(CIA)的流行情况进行了调查。结果表明:在检测的460份血清样品中,鸡传染性贫血病毒(CIAV)ELISA抗体总阳性率为80.65%,蛋鸡群、肉鸡群和地方鸡群CIAV ELISA检测抗体阳性率分别为77.45%、84.03%和82.14%。说明目前江西省各地饲养的鸡群中CIAV感染相当普遍;各鸡场的感染率有较大差别,最低的抗体阳性率只有5%,最高的阳性率达100%,肉鸡、蛋鸡、地方鸡CIAV抗体的阳性率无明显差别。     

浙江省宁波市部分鸡场鸡免疫抑制性疫病血清学调查

为了解禽白血病、禽网状内皮组织增生症和鸡传染性贫血在本地鸡群的感染情况,对宁波市7个区、县的15个鸡群进行了3种疫病4种抗体的血清学检测。结果显示:362份被检血清中,AB亚群禽白血病病毒(ALV-AB)抗体阳性率为55.0%,J亚群禽白血病病毒(ALV-J)抗体阳性率为21.5%,禽网状内皮组织增生症病毒(REV)抗体阳性率为32.0%,鸡传染性贫血病毒(CAV)抗体阳性率为66.8%;15个鸡场AB亚群禽白血病和鸡传染性贫血共感染率为100.0%;12个鸡场共感染了3种免疫抑制性疫病,混合感染率高达80.0%。调查结果表明免疫抑制病在宁波市鸡群中非常普遍。     

中国鸡群禽呼肠孤病毒抗体的检测与分析

为了解我国鸡群中禽呼肠孤病毒(Avian reovirus,ARV)的抗体水平,本研究利用ELISA方法对2010-2013年来自全国19个省市的鸡血清样品进行了ARV抗体检测。在检测的17 058份鸡血清样品中共检出ARV抗体阳性血清156 80份,阳性率为92.83%,其中免疫鸡群的阳性率为98.50%,非免疫鸡群的阳性率为74.72%。除山东省和广东省外,其他各个省市的样本阳性率均在90%以上。商品肉鸡、肉种鸡、商品蛋鸡和蛋种鸡的ARV抗体阳性率分别为72.66%,98.48%,93.40%和95.53%。部分地方品种鸡群的ARV抗体水平也较高。结果表明,我国鸡群ARV感染情况普遍存在,主要表现为一定比例的免疫鸡群抗体过高、未免疫鸡群存在较高的抗体阳性率。     

福建省规模化鸡场禽偏肺病毒感染情况的血清学调查

禽偏肺病毒(aMPV)是一种危害火鸡和鸡的新病原,为调查福建省规模化鸡场aMPV的感染情况,从福州市、莆田市、泉州市、漳州市、龙岩市和南平市18个规模化鸡场采集1 020份血样,用酶联免疫吸附试验(ELISA)进行aMPV抗体检测。结果表明,所调查地区的鸡群均已感染aMPV,抗体平均阳性率为62.2%(634/1 020),最高100%,最低为32.0%;蛋鸡和肉鸡均可感染aMPV,蛋鸡的抗体阳性率略低于肉鸡;商品代鸡群的抗体阳性率高于父母代;京红、海兰蛋鸡和本地鸡均可感染aMPV,其中本地鸡1的抗体滴度最高;aMPV抗体的log10滴度和抗体阳性率随着鸡群周龄的增长而逐渐升高。研究表明,所调查的福建规模化鸡场鸡群已经普遍感染aMPV,且感染较严重。     

安徽省部分地区鸡群禽偏肺病毒感染的血清学调查

为掌握禽偏肺病毒(aMPV)在安徽省鸡群中的感染状况,采用酶联免疫吸附试验(ELISA)对安徽省合肥、亳州、定远、舒城等地区的9个鸡场、7个不同品种(系)鸡群的296份血液样本进行了aMPV血清抗体检测。结果表明,所有被检鸡场均有aMPV感染,鸡场阳性率最高达100%,最低为20%;各品种(系)鸡均有感染,感染率最高的是青脚麻肉鸡,其次分别为科宝肉鸡、海兰蛋鸡、禽粤黄蛋鸡、淮南麻黄鸡、黄羽土鸡和新广麻肉鸡;其中蛋用型鸡血清样本总体阳性率为88.7%,明显高于肉用和兼用型鸡;公鸡和母鸡血清抗体阳性率均较高。研究结果表明,安徽省鸡群aMPV的感染已广泛存在,且不同地区、品种(系)、用途和性别的鸡群均较严重,应根据感染状况尽早制定相应的防控对策。     

用斑点杂交法同时检测鸡群中的CAV MDV和REV

为研究鸡传染性贫血病毒(CAV)在鸡群中的感染状况以及马立克氏病病毒(MDV)和网状内皮细胞增生病病毒(REV)在鸡群中的发病率，用斑点杂交法对山东省4个肉鸡场和2个肉种鸡场进行CAV、MDV和REV的检测，结果表明除一个肉种鸡场没有检测出REV以外，其他鸡场均同时检测出CAV、MDV和REV，并且发现直接从病科中检测CAV的阳性率(20％)远远低于将病科接种SPF鸡胚后的检出率(80％)。     

我国白羽肉用型鸡群中CAV、REV和REOV感染状况的血清学调查

为了解鸡传染性贫血病毒（CAV）、禽网状内皮增生病病毒（REV）和呼肠孤病毒（REOV）在我国白羽肉用型鸡中的感染状态，在2003—2004年，检测了来自5省市8个公司不同年龄鸡群血清样品中3种病毒抗体的存在状况。结果表明，在送检的75个鸡群中，对CAV、REV和REOV呈现抗体阳性的鸡群分别有64个（85．3％）、36个（48％）和74个（96％）。在总共检测的1764份血清样品中，对这3种病毒的平均抗体阳性率分别为51．4％、9．8％和75．1％。在1日龄雏鸡，对CAV和REOV的平均母源抗体阳性率可达100％和81．1％，但对REV只有7．4％。抗体阳性率随年龄变化的动态分析表明，对REV和REOV的母源抗体在出壳后2～3周内消失，而对CAV的母源抗体则可持续3～4周。对CAV和REOV的抗体从5周龄起再次出现，到20周龄时，所有送检鸡群全部阳性，平均阳性率在90％以上。有近一半送检鸡群对REV呈现抗体阳性，抗体阳性率普遍较低，即使在达到开产年龄后，仍还有很高比例鸡为抗体阴性，即对REV仍为易感鸡。研究表明，我国多数鸡群中都同时存在着这3种病毒的感染，但它们在感染的程度和动态等流行病学特点上显著不同，应根据鸡群中抗体的阳性率分别采取不同的措施。     

山东省白羽肉鸡中MDV、REV、CAV和ARV感染状况的病原学调查

为了解鸡马立克氏病病毒(MDV)、鸡传染性贫血病毒(CAV)、禽网状内皮增生病病毒(REV)和禽呼肠孤病毒(ARV)在山东省白羽肉用型鸡中的流行情况,试验采用地高辛标记的核酸探针-斑点杂交法对淘汰的商品肉鸡、病死商品肉鸡及淘汰肉种鸡进行了上述4种病毒病原的检测。结果表明:ARV主要以单一形式感染,在病死商品肉鸡中感染率最高(30.07%),在3种类型鸡中ARV感染率高于MDV,REV,CAV。MDV在淘汰肉种鸡中感染率(12.82%)高于其他2种鸡群,而REV,CAV,ARV感染率在病死商品肉鸡中最高。混合感染亦相当普遍,以淘汰肉种鸡最高(混合感染率达10.25%),高于任一病毒单独感染率,其次为病死商品肉鸡。     

应用免疫防制技术控制鸡传染性贫血病

鸡传染性贫血病 ( Chicken Infectious Anemia,CIA)是由鸡贫血病毒 ( Chicken Anemia Virus,CAV)引起的 ,其特征性病变为骨髓黄化 ,胸腺萎缩 ,出现造血机能障碍和免疫机能损害 [1,2 ]。自 1 979年从日本发现和分离到 CAV以来[3 ] ,德国、英国、美国、澳大利亚、荷兰和以色列报道了本病的存在 ,对 CAV感染的流行病学调查已表明 ,世界各地鸡群中 ,对 CAV的感染率都相当高 ,甚至在曾经认为是 SPF鸡群中也有 40 %～ 5 0 %表现出 CAV抗体阳性。我国于 1 992年首次分离到该病毒[4 ] ,以后陆续有报道。在许多地区鸡群 CIA血清抗体的阳…     

海兰（褐）父母代种鸡引入青海高寒地区的饲养试验

对从山东引入青海高寒地区的海兰（褐）父母代鸡进行了饲养试验。结果表明,引入鸡32周龄最高产蛋率达78%,25周龄后种蛋受精率达88%,入孵蛋的孵化率达75%,母鸡1～18周龄成活率为94%,19～60周龄成活率为92%。引入鸡的各项指标基本达到山东标准。     

Cloning and expression of chicken anemia virus VP3 protein in Escherichia coli

Purification of chicken anemia virus (CAV) VP3 protein, expressed in a prokaryotic expression system as histidine-tagged fusion protein is demonstrated in the present study. CAV particle was obtained from infected liver of chicken and DNA was extracted. The VP3 protein gene was amplified from the extracted DNA by polymerase chain reaction (PCR) and cloned. The recombinant expression construct (pTrc-VP3) was identified by PCR and sequencing analysis. Expression of VP3 protein with a molecular mass of approximately 21kDa was confirmed by Western blotting analysis with CAV-specific antibodies. The in vitro expressed VP3 protein was purified to near homogeneity by elution from the gel, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. The purified VP3 protein was recognized by CAV antibodies in a Western blotting assay. This finding indicates that recombinant VP3 expressed in the pTrcHis2 vector system can be used as antigen to detect anti-CAV antibodies.     

Serological evidence of chicken infectious anemia virus in the United States at least since 1959

A retrospective, serological survey was performed to determine an approximate time frame for when chickens were first exposed to chicken anemia virus (CAV) in the southeastern United States. A serum collection covering most of the period between 1959 and 2005 was available for the present study. These sera were obtained from adult chicken flocks that were maintained in experimental chicken farms at Auburn University's Department of Poultry Science. Sera were tested for the presence of CAV-specific antibodies using a commercially available competitive enzyme-linked immunosorbent assay (ELISA) kit. Values <0.6 were considered positive. Fresh sera obtained from hens in 2005 showed 45.5% negative and 54.5% positive for CAV antibodies. The assessment of serum samples covering the time period of 1959 through 1979 resulted in most sera being positive for CAV antibodies. The percentage of positive samples between years varied from 43% to 100%. These serological results support assumptions based on circumstantial evidence that CAV must have been present in the United States long before its first isolation in 1989.     

Detection of chicken anemia virus in the gonads and in the progeny of broiler breeder hens with high neutralizing antibody titers

Previous evidence for the presence of chicken anemia virus (CAV) in the gonads of immune specific-pathogen-free chickens raised the question whether this occurs also in commercial breeders. The presence of CAV was investigated by nested PCR in the gonads and spleens of hens from two 55- and 59-week-old, CAV-vaccinated (flocks 2 and 3), and two 48- and 31-week-old non-vaccinated broiler breeder flocks (flocks 1 and 4). In addition, lymphoid tissues of 20-day-old embryos from these hens were also investigated for the presence of CAV. CAV was detected in the gonads and of 5/6 and 11/22 of the vaccinated hens and in some hens also in the spleen alone. Embryos from 7/8 and 5/18 of these hens were positive. In the non-vaccinated flocks, CAV was detected in the gonads of 11/34 and 10/10 hens in flocks 1 and 4, respectively. In addition, 11 birds in flock 1 had positive spleens. CAV DNA was detected in 3/11 and 2/10 of their embryos. CAV-positive gonads and embryos were detected in samples from hens with moderate as well as high VN antibody titers. Vaccinated chickens positive for CAV in the gonads and in their embryos had VN titers ranging from >1:512 to <1:2048. In non-vaccinated chickens, the VN titers of CAV positive chickens ranged from 1:128 to 1:4096. These results demonstrate that CAV genome can remain present in the gonads of hens in commercial broiler breeder flocks even in the presence of high neutralizing antibody titers that have been associated with protection against CAV vertical transmission. It also suggests that transmission to the progeny may occur irrespectively of the level of the humoral immune response in the hens.     

四川地区蛋鸡孵化场沙门氏菌调查

通过对四川不同地区的4个蛋种鸡孵化场进行沙门氏菌感染调查,发现4个蛋种鸡孵化场中弱雏身上的沙门氏菌分离率最高(分别为25.2%、0、13.7%、5.3%),对应孵化场提供的早期死亡雏鸡身上的沙门氏菌分离率也较高(分别为25.3%、7.8%、16.5%、8.6%)。选择19株沙门氏菌用21种抗生素进行耐药性检测,发现该菌只对头孢类部分药物及个别其他类别药物敏感,而对喹诺酮类、磺胺类、大环内酯类、氨基糖苷类的大部分药物耐药。表明对蛋种鸡孵化场沙门氏菌耐药性的控制迫在眉睫。     

PCR、斑点杂交及间接免疫荧光试验对鸡传染性贫血病临床诊断的应用比较

应用能特异性扩增出鸡传染性贫血病毒（ Ｃ Ａ Ｖ） ０５８ ｋｂ Ｄ Ｎ Ａ 的已知引物，对江苏某地区疑为 Ｃ Ａ Ｖ感染的 １５～３０ 日龄病鸡的肝 Ｄ Ｎ Ａ 样品进行了 Ｐ Ｃ Ｒ 扩增。结果，在被检的 ２０ 份样品中，有 ６ 份为 Ｐ Ｃ Ｒ 阳性，阳性率 ３０％ 。利用地高辛标记的 ０８５ ｋ ｂ 的 Ｃ Ａ Ｖ 核酸探针对相同样品进行斑点杂交，结果与 Ｐ Ｃ Ｒ 扩增相同。对应的病鸡血清经间接免疫荧光试验（ Ｉ Ｉ Ｆ Ａ）发现，有 ７ 份为 Ｃ Ａ Ｖ 抗体阳性，与 Ｐ Ｃ Ｒ 扩增结果的符合率为 ７７％ 。初步结果表明，江苏某地区存在 Ｃ Ａ Ｖ 感染， Ｉ Ｉ Ｆ Ａ 与 Ｐ Ｃ Ｒ 的结果有差异     

黄金褐商品蛋鸡引入青海省东部地区后生产性能观测

在青海省海东地区某部队养鸡场观测黄金褐商品蛋鸡的生产性能，并总结其饲养管理。结果表明雏鸡成活率为98.95%，育成期成活率为96.95%，产蛋期成活率为95.15%，饲养日增产蛋率79.1%，平均最高峰产蛋率92%，平均蛋重61.5g。该品种比较适应青海高海拔、寒冷的地理环境，且有推广价值。     

Village chicken production in Turkey: Tokat province example

The aim of this work was to reveal the current form of village chicken production in Tokat province of Turkey. A survey was applied to 153 randomly selected farmers of 5 subdistricts in Tokat province. The ratios of domestic fowls in the survey region were as follows: hen 98.83%, goose 0.65%, turkey 0.29% and duck 0.16% (P < 0.01). Feather colours of laying hens were white (2.76%), brown (8.63%) and mixed color (88.60%). The hen farms in this region consisted of native breeds (91.42%), commercial breeds (5.71%) and their crosses (2.85%). The mean egg weight of the village hens was between 30 and 40 g. Wheat (65.73%) and mixed (wheat, barley, maize and kitchen refuse) feed (34.22%) were used to supplement the hens (P < 0.01). For producing natural chicks, the hens were brooded between 1.10 and 1.46 times/year, 1.31 on average. For each brooding, the number of placed eggs under the broody hens was between 11.39 and 12.42 (P < 0.05).     

Molecular epidemiology of chicken anemia virus (CAV) in southeastern Chinese live birds markets

Between January 2004 and December 2005, cloacal swabs from essentially healthy chickens and silky chickens from live birds markets in Guangdong and Hunan provinces in southeastern China were screened for chicken anemia virus (CAV) by polymerase chain reaction. Phylogenetic analysis of the major structural protein VP1 sequences showed no clear genotype cluster and no correlation with the geographic origin of CAV strains. Virus evolution at the amino acid level was very slow, which corresponds to a strong negative selection of the VP1 gene in China and worldwide. A high proportion (87%) of birds was CAV positive, suggesting that many farms in the region were infected. Further investigations are necessary to evaluate the economic losses caused by CAV and the cost-benefit of vaccination.     

Oral infection with chicken anemia virus in 4-wk broiler breeders: lack of effect of major histocompatibility B complex genotype

The pathologic consequences of chicken anemia virus (CAV) oral inoculation in 4-wk-old broiler breeders of different major histocompatibility B complex (MHC) genotypes were evaluated. MHC B complex was determined by hemagglutination and sequence-based typing. Clinical signs, serology, gross lesions, histopathologic analysis, and CAV genome quantification were used to evaluate disease progression. Clinical disease was not apparent in the inoculated broilers throughout the experimental period. At 14 days postinoculation, antibodies against CAV were detected in 26.4% (29/110) of the inoculated birds. The distribution of percent positive was 34.6% (9/26) and 32.3% (10/31) of the chickens with B A9/A9 and B A9/A4 MHC genotypes, respectively, and seroconversion in six other genotypes was 19% (10/53). These differences among MHC genotypes for specific seroconversion rate were not statistically significant. CAV genomes were detected in the thymus of 87.7% (93/110) of the inoculated birds with no statistically significant differences between MHC genotypes. Mild thymic lymphocytolysis, lymphedema, and medullary hemorrhage were observed in the inoculated chickens. Histomorphometric analysis showed that cortical lymphocyte-to-parenchyma ratios did not differ between inoculated and uninoculated groups or among MHC genotypes. Similar findings have been reported previously in white-leghorn chickens of similar age, suggesting that broilers show a similar resistance to the effects of CAV infection at this age. The absence of significant clinical and pathological changes in the orally inoculated broilers at this age contrasts with CAV-associated thymus damage seen frequently in condemned commercial broilers at harvest.