鸡新城疫免疫失败的原因及采取的对策

免疫接种是防制新城疫的重要手段,然而在新城疫免疫接种实践中,由于新城疫疫苗种类较多、免疫方法不一,新城疫免疫失败时有发生,导致新城疫发生。造成新城疫免疫不成功的因素有很多,现结合在实践中的一些研究就免疫失败及其对策进行分析,分述如下。     

黄芪多糖对鸡抗病能力的影响

黄芪多糖是一种从豆科类植物黄芪或膜荚黄芪的根茎中提取而来的水溶性多糖成分,具有祛湿、抗病毒、抗氧化、抗辐射、增强免疫力等多种生物学作用,也可以作为免疫增强剂和免疫佐剂,在增强鸡的免疫力方面发挥了重要作用。本文综述了黄芪多糖对鸡抗病能力的影响及其作用效果的影响因素和今后的发展方向,为黄芪多糖在鸡生产中的应用研究提供参考。     

Studies on genetic resistance to Marek's disease in the domestic chicken

Inoculation trials using the HPRS‐B14 and HPRS‐16 strains of classical and acute Marek's disease (MD) respectively, were undertaken on single sire families of commercial chickens. It was demonstrated that both sires and dams had a significant effect on the susceptibility of their progeny to Marek's disease. It is suggested that the genetic constitution of the chicken plays a rôle in controlling its susceptibility to MD. The susceptibility to MD of females was significantly greater than males.

Members of some of the single sire families used in one Marek's disease trial became naturally exposed to Marek's disease in a trial designed to examine the effect of sire families on the incidence of leukosis. There was a significant positive correlation between the incidence of Marek's disease in members of single sire families infected by inoculation and by natural exposure. There was no correlation between incidence of Marek's disease and the incidence of tumours of the leukosis/sarcoma complex.

The range in incidence of MD in single sire families suggested that there was adequate heterogeneity in the commercial lines of chicken to warrant a selection programme for resistance to Marek's disease. The absence of any significant correlation between resistance to Marek's disease and a number of production traits suggested that such a programme should have little effect on these traits.

A negative correlation between incidence of Marek's disease in single sire families and mean latent period was shown. The use of a parameter including a measure of mean latent period as well as incidence of MD resulted in greater sire variance ratios than the use of incidence alone.     

白细胞介素2对固始鸡十二指肠黏膜免疫增强作用

以父母代固始鸡为试验材料,用添加不同剂量的白细胞介素2(IL-2)佐剂的鸡志贺氏菌苗对试验鸡进行分组免疫,应用免疫组织化学技术,通过Owin图像处理系统对鸡十二指肠内分泌型免疫球蛋白A(SIgA)阳性细胞反其分泌物的分布和阳性面积进行系统分析.结果表明,SIgA阳性细胞主要分布于十二指肠肠黏膜的固有膜及肠腺腔中,在志贺菌组中添加IL-2能够提高SIgA细胞的分泌,从而提高动物体的免疫能力,且以IL-2的添加剂量在50μg时对增加志贺菌苗的免疫性效果最佳.     

Immunological differences between layer- and broiler-type chickens

In commercial poultry husbandry, alternatives for the use of antibiotics and vaccines are under investigation, which preferably have to be applicable for both layer- and broiler-type chickens. There are indications that the defense mechanisms vary between layer- and broiler-type chickens. Therefore, the difference in immune response between layer- and broiler-type chickens of the same age was investigated, using TNP-KLH (trinitrophenyl-conjugated keyhole limpet hemocyanin) as antigen without adjuvant. First different routes of immunization (intravenously, intramuscular, subcutaneous and ocular) were examined to find out which immunization route gives the highest antibody titers. The intravenous immunization route resulted in higher TNP-specific antibody responses than the other immunization routes tested and therefore this immunization route was used in both following experiments. In order to investigate the optimal dose of antigen needed for immunization, a dose-response curve in broiler- and layer-type chickens was completed. The humoral immune response was measured in serum by a TNP-specific ELISA and the in vitro cellular immune response by an antigen-specific lymphocyte proliferation assay.The antibody response of layer- and broiler-type chickens appeared to differ, not only in optimal dose and response, but also in kinetics of the response itself. Broiler chickens generated higher IgM anti-TNP titers whereas layer-type chickens generated higher IgG anti-TNP titers. This specific antibody response in broiler-type chickens did not last as long as in layer-type chickens. The TNP-specific cellular immune response was detectable in layer-type chickens, but not in broilers. Both types generate a non-specific cellular immune response, although this response in broilers is lower than in layer-type chickens.From these results, we conclude that broilers primarily respond to TNP-KLH with a high IgM antibody response whereas layer-type chickens respond with a high IgG response. In addition, the cellular response of layer-type chickens is much higher than the response of broilers. The results suggest that broilers are specialized in the production of a strong short-term humoral response and layer-type chickens in a long-term humoral response in combination with a strong cellular response, which is in conformity with their life expectancy.     

Immunological and gene expression responses to a Salmonella infection in the chicken intestine

Besides infection in humans, Salmonella enteritidis can also cause serious illness in young chickens. However, the genetic and immunological parameters important for the disease in chickens are not well characterized. In this study, processes in the chicken intestine in response to a Salmonella infection were investigated in two different chicken lines. One-day-old chickens were orally infected with Salmonella. T-cell subpopulations, phagocytic properties of intestinal mononuclear cells and RNA expression levels of the jejunum were investigated. The two chicken lines differed in the amount of cfu in the liver and growth retardation after the infection. Differences in phagocytic activity of intestinal mononuclear cells were found between control and Salmonella infected chickens. The number of CD4+ T-cells of the intestine decreased after the Salmonella infection in one chicken line, while the number of CD8+ T-cells increased in both chicken lines, but the time post infection of this increase differed between the lines. In one chicken line the expression levels of the genes carboxypeptidase M and similar to ORF2 decreased after the Salmonella infection, which might be related to a decrease in the amount of macrophages. With the microarray, ten genes were found that were regulated in only one of the chicken lines, while we found six genes regulated in response to the infection in both chicken lines. So differences in genetic background of the chickens influence the intestinal host response of the Salmonella infection as observed by phagocytic activity, gene expression and changes in the number of T-cell subpopulations and macrophages.     

黄芪超细微粉对雏鸡免疫功能的影响

为探讨黄芪的免疫增强作用,将黄芪制备成超细微粉添加到雏鸡饲料中、饮水中以及新城疫油乳剂灭活苗中,通过测定雏鸡的体重、雏鸡对新城疫疫苗的免疫力,研究其对雏鸡免疫功能的影响.试验将240只1日龄健康海兰褐蛋雏鸡分为实验组和对照组.分别于7日龄、14日龄、21日龄、28日龄、35日龄、42日龄随机抽取10只鸡称重,翅静脉采血0.5 mL,分离血清,用血凝抑制试验测定血清NDV抗体水平.研究结果表明:与对照组相比.试验组鸡的体重增加、血清抗NDV抗体效价平均值也有不同程度的提高.     

Strain differences in whole-body protein turnover in the chicken embryo.

1. Whether or not there is a strain difference in embryonic whole-body protein turnover rates was tested using the chicken embryos of Rhode Island Red carrying a sex-linked dwarf gene (dwarf), White Leghorn (layer), and White Cornish X White Plymouth Rock (broiler) strains on day 12 of incubation. 2. Whole-body protein synthesis was estimated by injecting L-[15N]-phenylalanine either intraperitoneally or intravenously on day 12 of incubation in order to investigate the effect of the route of isotope administration. The results showed that the values for fractional and absolute synthesis rates were approximately 13% higher by intravenous injection than by intraperitoneal injection. 3. Whole-body protein turnover, both in terms of fractional and absolute rates, was significantly faster in dwarf than in broiler embryos, with intermediate values in layer embryos, although no growth differences were observed on day 12. 4. Difference in egg weight, measured before incubation, did not affect protein turnover. 5. It was concluded that the strain difference manifested in whole-body protein turnover of the chicken embryo would probably be a reflection of differences in genetic background.     

Genetic assessment of inbred chicken lines indicates genomic signatures of resistance to Marek's disease

Background: Marek's disease(MD) is a highly contagious pathogenic and oncogenic disease primarily affecting chickens. However, the mechanisms of genetic resistance for MD are complex and not fully understood. MD-resistant line 6_3 and MD-susceptible line 7_2 are two highly inbred progenitor lines of White Leghorn. Recombinant Congenic Strains(RCS) were developed from these two lines, which show varied susceptibility to MD.Results: We investigated genetic structure and genomic signatures across the genome, including the line 6_3 and line7_2, six RCSs, and two reciprocally crossed flocks between the lines 6_3 and 7_2(F1 6_3× 7_2 and F1 7_2× 6_3) using Affymetrix~? Axiom~? HD 600 K genotyping array. We observed 18 chickens from RCS lines were specifically clustered into resistance sub-groups distributed around line 6_3. Additionally, homozygosity analysis was employed to explore potential genetic components related to MD resistance, while runs of homozygosity(ROH) are regions of the genome where the identical haplotypes are inherited from each parent. We found several genes including SIK, SOX1, LIG4, SIK1 and TNFSF13B were contained in ROH region identified in resistant group(line 6_3 and RCS), and these genes have been reported that are contribute to immunology and survival. Based on F_(ST) based population differential analysis, we also identified important genes related to cell death and anti-apoptosis, including AKT1, API5, CDH13, CFDP and USP15,which could be involved in divergent selection during inbreeding process.Conclusions: Our findings offer valuable insights for understanding the genetic mechanism of resistance to MD and the identified genes could be considered as candidate biomarkers in further evaluation.     

种鸡葡萄球菌病病因浅析

鸡葡萄球菌病一年四季均可发生,但以春季及气候多变季节多发。每年3～6月份种鸡在育成、产蛋过程中,很容易发生葡萄球菌病,给种鸡生产带来巨大影响及损失。     

Modeling genetic differences of combined broiler chicken populations in single-step GBLUP

The introduction of animals from a different environment or population is a common practice in commercial livestock populations. In this study, we modeled the inclusion of a group of external birds into a local broiler chicken population for the purpose of genomic evaluations. The pedigree was composed of 242,413 birds and genotypes were available for 107,216 birds. A five-trait model that included one growth, two yield, and two efficiency traits was used for the analyses. The strategies to model the introduction of external birds were to include a fixed effect representing the origin of parents and to use unknown parent groups (UPG) or metafounders (MF). Genomic estimated breeding values (GEBV) were obtained with single-step GBLUP using the Algorithm for Proven and Young. Bias, dispersion, and accuracy of GEBV for the validation birds, that is, from the most recent generation, were computed. The bias and dispersion were estimated with the linear regression (LR) method,whereas accuracy was estimated by the LR method and predictive ability. When fixed UPG were fit without estimated inbreeding, the model did not converge. In contrast, models with fixed UPG and estimated inbreeding or random UPG converged and resulted in similar GEBV. The inclusion of an extra fixed effect in the model made the GEBV unbiased and reduced the inflation. Genomic predictions with MF were slightly biased and inflated due to the unbalanced number of observations assigned to each metafounder. When combining local and external populations, the greatest accuracy can be obtained by adding an extra fixed effect to account for the origin of parents plus UPG with estimated inbreeding or random UPG. To estimate the accuracy, the LR method is more consistent among scenarios, whereas the predictive ability greatly depends on the model specification.     

鸡贫血病—法氏囊病疫苗免疫母鸡后子代雏鸡的免疫学变化

本项目应用现代免疫学新技术对鸡传染性贫血病（CIA）-传染性法氏囊病（IBD）疫苗联合免疫母鸡后,其子代雏鸡外周血液T、B细胞数量和IgG、IgM、IgA含量法及法氏囊、胸腺、脾脏、盲肠扁桃体、哈德尔腺的T细胞和IgG、IgM、IgA抗体生成细胞数量以及泪液、气管液、胆汁、肠液的IgA、IgM、IgG含量的变化进行了动态研究。结果发现,CIA-IBD疫苗联合免疫母鸡后,其子代雏鸡外周血液、免疫器官组织和局部体液的上述各项指标均不同程度地高于未免疫的相应对照雏鸡。表明CIA-IBD疫苗免疫母鸡后,其子代雏鸡的体液免疫和细胞免疫功能明显增强,而CIAV-IBDV强毒攻击后,未免疫的子代雏鸡,其外周血液,免疫器官组织和局部体液的各项免疫学指标均明显低于疫苗免疫攻毒的子代雏鸡,这与未免疫雏鸡缺乏特异性抗体,强毒攻击后,雏鸡免疫器官组织广泛损害,淋巴细胞变性坏死等有关。     

鸡与鸭重要免疫相关基因结构与功能差异及其禽流感抗性关联分析

禽流感(AI)是禽流感病毒(AIV)引起的一种急性传染病。天然免疫是宿主抵抗病毒感染的第一道防线,在机体抗病毒感染过程中发挥重要作用。鸭和鸡是H5N1AIV感染和传播的主要宿主,但鸭对AI禽流感的抗性远大于鸡,目前公认与其机体天然免疫相关基因有关。比较这两种亲缘关系相近模式生物的遗传结构,可以揭示AI抗性差异的分子基础。本文比较分析鸭和鸡主要免疫相关基因的结构与功能及其在AIV抗性差异方面的潜在作用,为AI防控新技术研究提供理论基础。     

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、     

药物治疗鸡病失败的原因

长期以来，我国养鸡业一直受到疫病的困扰，特别是近几年来，鸡病越来越多，病因越来越复杂。而对鸡病的困扰，养鸡场用药量越来越大，用药时间也越来越长，虽然使用大量药物也常常控制不住病情，严重影响了养鸡业的健康发展。下面对目前药物治疗鸡病失败的原因作一分析。１诊断用药有误鸡病有病毒性疾病、细菌性疾病及寄生虫病之分。有时诊断错误，导致用药无效。病毒性疾病应主要考虑免疫接种预防，一些抗病毒药物疗效尚在验证之中。细菌性疾病可以用药物进行治疗。但每一种抗生素都有一定的抗菌谱，有时病原微生物对所选择的抗生素不敏感…     

治疗鸡"花斑肾"病的体会

2004年月10月下旬至2007年1月，我县肉鸡、麻鸡等普遍发生了以“花斑肾”为主要病变的疾病，接诊87棚，计32万只，现将该病的发生、防治等情况报告如下：