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。     

Comparisons of serologic responses of white Leghorn and New Hampshire red chickens to purified lipopolysaccharides of Pasteurella multocida

White leghorn and New Hampshire red chickens were inoculated with purified lipopolysaccharides of 14 serotypes of Pasteurella multocida to determine their ability to produce serotype-specific antisera for somatic antigen typing. Specific antisera were made by both breeds of chicken to lipopolysaccharides of serotypes 1, 3, 4, 6, 8, and 16. No specific antisera were made against lipopolysaccharides of serotypes 2, 5, 7, 12, and 14. Lipopolysaccharides of serotypes 10 and 11 failed to stimulate antibody production. White leghorns were more responsive than New Hampshire red chickens. White leghorn antisera had higher titers to lipopolysaccharides in passive hemagglutination tests and produced more intense precipitin reactions with heat-stable antigens in the gel-diffusion-precipitin test.     

Genetic diversity of Forest and Savannah chicken populations of Ghana as estimated by microsatellite markers

The characterization of indigenous animal genetic resources is a requisite step in providing needed information for the conservation of useful genotypes against future needs. Thus, in this study, 22 microsatellite markers were used to genotype 114 local chickens from the Forest (n = 59) and Savannah (n = 55) eco‐zones of Ghana and the results compared to those of the ancestral red junglefowl (n = 15) and two European commercial chicken populations – a broiler (n = 25) and white leghorn (n = 25). A total of 171 alleles were observed, with an average of 7.8 alleles per locus. The local Ghanaian chickens showed higher diversity in terms of the observed number of alleles per locus (6.6) and observed heterozygosity (0.568) compared with the combined control populations (6.0 and 0.458, respectively). However, Wright's F‐statistics revealed negligible genetic differentiation (F_ST) in local Ghanaian chicken populations. In addition, 65% of the Savannah chickens were inferred to be more likely from the Forest, suggesting a south‐north dispersal of chickens from their probable original location in the Forest zone to the Savannah areas. It is concluded that the Forest and Savannah chickens of Ghana are a single, randomly mating unselected population, characterized by high genetic diversity and constitute a valuable resource for conservation and improvement.     

用微卫星标记分析贵州地方鸡种的遗传多样性及亲缘关系

利用20个微卫星座位对贵州12个地方鸡种和隐性白洛克进行遗传分析,得到各品种的等位基因频率、平均杂合度、多态信息含量及品种间的Nei氏标准遗传距离,并进行了聚类分析。结果表明:13个鸡种在各微卫星座位上的遗传杂合度均有差异,平均遗传杂合度为0.6885(贵州地方鸡种为0.6915);平均多态信息含量为0.6297(贵州地方鸡种为0.6326),说明贵州地方鸡种遗传多样性较隐性白洛克丰富。UPGMA聚类分析结果显示,13个鸡种分为2大类群,隐性白洛克独自构成一个类群,12个贵州地方鸡种为另一个类群,12个贵州地方鸡种进一步可分为4个小类群。研究结果对贵州地方鸡种资源的评估、保存和利用具有一定的指导意义。     

鸡Apo VLDLⅡ基因内含子Ⅰ的多态性研究

本研究根据鸡Apo VLDL-Ⅱ基因内含子Ⅰ的基因序列设计3对引物,分别采用PCR-RFLP、PCR-SSCP技术对文昌鸡、如皋黄鸡、丝羽乌骨鸡、安卡肉鸡及红色原鸡5个鸡种进行多态性研究。结果表明,鸡Apo VLDL-Ⅱ基因内含子Ⅰ存在4处突变,分别为:1950处G/A、2522处A/C、2705处A/C及2793处C/T。统计结果显示:安卡肉鸡基因型频率的分布与如皋黄鸡、红色原鸡存在显著差异,文昌鸡基因型频率的分布与乌骨鸡差异不显著,除安卡肉鸡外所有鸡种均处于Hardy-Weinberg平衡状态。     

利用微卫星标记分析贵州地方鸡种的遗传多样性及亲缘关系

利用7个微卫星标记对12个贵州地方鸡种及1个引入鸡种的遗传多样性进行了检测，分析了各标记座位上的等位基因及频率、基因杂合度、平均基因杂合度、多态信息含量、平均多态信息含量及群体间的亲缘关系。结果表明：13个种群在7个标记座位上的等位基因及频率等均存在一定差异。其中，瑶山鸡的平均基因杂合度最高，引入鸡种隐性白洛克的平均基因杂合度最低，其余鸡种介于其间。平均多态信息含量的分析结果与此类似，说明瑶山鸡的遗传多样性最为丰富。模糊聚类的结果表明，13个鸡种分为2大类群，隐性白洛克独自为1个类群，12个贵州地方鸡种构成1个类群。12个贵州地方鸡种又可进一步分为2个小类群：其中1个小类群由兴义土鸡、矮脚鸡首先聚在一起，然后依次聚上黔东南小香鸡、黔东南小香乌骨鸡构成；高脚鸡、瑶山鸡、威宁鸡、竹乡鸡、竹乡乌骨鸡、黑羽乌蒙乌骨鸡、乌蒙鸡、麻羽乌蒙乌骨鸡则构成另一个小类群。     

基于线粒体控制区的鸡不同杂交组合遗传多样性研究

旨在探讨鸡不同杂交组合线粒体控制区（mtDNA D-loop区）的遗传多样性和单倍型特性。选取固始鸡和隐性白羽鸡及其正、反交F1代、藏鸡以及F2代等6个群体共387个个体的mtDNA D-loop区进行测序,分析其遗传规律和单倍型特性,并与不同红色原鸡亚种进行聚类,分析其母系起源。结果显示,6个群体D-loop区全序列大小为1 231 bp,共检测到28个多态位点和1个C碱基缺失,共构成19种单倍型,分为A、B、C和E 4个单倍型群,其中,固始鸡和反交F1代主要为A、C单倍型,固始鸡A、C单倍型比例分别为53.42%和46.58%,反交F1代A、C单倍型比例分别为50.75%和49.25%;隐性白羽鸡、正交F1代和F2代优势单倍型均为E单倍型,占比分别为48.89%、48.84%和50.00%。6个鸡群体单倍型多样度（Hd）在0.496~0.729之间,核苷酸多样度（Pi）在0.003 40~0.005 41之间,Hd值和Pi值最大的均为正交F1代,其次为隐性白羽鸡和F2代,固始鸡和反交F1代群体遗传多样性接近。聚类分析显示,A、B单倍型群与滇南亚种交叉聚为一枝;E单倍型群与印度亚种交叉聚为一枝;C单倍型群与印度亚种、指名亚种、印尼亚种以及滇南亚种聚为一枝。结果提示,mtDNA D-loop区遵循严格的母系遗传,后代的遗传多样性和单倍型比例与其母本基本一致;我国家鸡群体具有多个红色原鸡母系起源,且主要起源于原鸡滇南亚种。     

鸡SH3RF2插入/缺失等位基因在中国地方鸡种中频率分布研究

中国地方鸡种资源丰富,风味较优,但存在生长速度慢、饲料效率低等缺点,因此为了加速我国地方鸡种和肉鸡品种的遗传改良,分子标记技术得到了广泛应用。已知SH3RF2基因的插入/缺失突变与肉鸡生长和体重密切相关,因此本试验对分布在我国各地的15个地方鸡品种进行了SH3RF2基因的等位基因频率检测,以确定SH3RF2基因在我国地方鸡种中的等位基因分布情况,继而将SH3RF2基因用于鸡生长性状的选择的分子育种标记。研究结果发现所检测地方鸡种和肉鸡品种均是非缺失的纯合子,没有发现缺失的等位基因。要利用SH3RF2基因对中国地方鸡种进行选择,可能需要通过杂交等手段将缺失型等位基因导入我国地方鸡种的群体之中。     

Pathogenesis of rotavirus infection in various age groups of chickens and turkeys: clinical signs and virology

Age-related susceptibility patterns of turkeys, broilers, and specific pathogen-free (SPF) White Leghorn chickens to experimentally induced infection with turkey or chicken rotavirus isolates were compared. The following determinants were evaluated: clinical signs, onset and duration of virus production, viral titers, involvement of intestinal villi in the replication of the virus, and the development of antibodies against the virus. Older turkeys and chickens were more susceptible than were their younger counterparts, turkeys were more susceptible than were broiler and White Leghorn chickens (regardless of age), and broiler chickens were slightly more susceptible than were age-matched White Leghorn chickens. Turkeys developed diarrhea, accompanied by high viral titers within 1 day after inoculation with virus. Viral antigen was found in the epithelial cells of the intestinal villi throughout the intestinal tract and some cells of the cecal tonsils. Antibodies could be detected as early as 4 to 5 days after inoculation. These findings were more pronounced in turkeys inoculated at 112 days of age than in birds inoculated at a younger age. Age-related susceptibility patterns were similar in White Leghorn and broiler chickens. Infection was subclinical in birds less than 56 days old, whereas older birds developed soft feces. Egg production in the White Leghorn chickens decreased after being inoculated with virus at 350 days of age.     

Allele‐specific PCR typing and sequencing of the mitochondrial D‐loop region in four layer breeds

This study aimed to investigate the ability of single nucleotide polymorphism (SNP) haplotypes in chicken mtDNA for presumption of the origins of chicken meat. We typed five SNPs of the D‐loop region in mtDNA by allele‐specific PCR (AS‐PCR) in 556 hens, that is 233 White Leghorn (WL), 50 Dekalb‐TX35 (D‐TX), 140 Barred Plymouth Rock (BPR) and 133 Rhode Island Red (RIR) kept in the National Institute of Livestock and Grassland Science (NILGS, Tsukuba, Japan). Five haplotypes were observed among those chickens by AS‐PCR. WL, D‐TX, BPR and RIR displayed three, two, one and four SNP haplotypes, respectively. By a combination of the haplotypes by AS‐PCR and the breeds, these chickens were classified into 10 groups. After the D‐loop was sequenced in two chickens from every group (20 individuals), 15 SNP sites (including one insertion) and eight sequence haplotypes were observed. In conclusion, haplotype variation was observed in and among the layer breeds of the NILGS. This study demonstrates that SNP haplotypes in mtDNA should be appropriate for the presumption of the origins of chicken meat.     

IGFBP-3基因在两个品种鸡组织中的表达及其与生长性状的相关性分析

为研究IGFBP-3基因表达与鸡生长性状的相关性,以生长速度差异较大的花山麻鸡和清远麻鸡两个黄羽肉鸡品种为研究素材,用实时荧光定量PCR法检测胚胎期和出雏后两个品种鸡胸肌和肝脏中IGFBP-3基因的表达规律,并将其与体重、胸肌重和肝脏重进行相关性分析。结果表明,在9胚龄时两个品种鸡胸肌和肝脏中均可检测到IGFBP-3基因表达,同一胚龄或日龄品种内组织间比较,胚胎期两个品种鸡胸肌IGFBP-3 mRNA表达量均高于肝脏,出雏后肝脏IGFBP-3 mRNA表达量迅速上升,胸肌IGFBP-3 mRNA表达量下降,两个品种鸡肝脏IGFBP-3 mRNA表达量均极显著高于胸肌（P<0.01）;组织中IGFBP-3 mRNA表达量与组织重量和体重相关研究表明,两个品种鸡肝脏IGFBP-3 mRNA表达量与其胸肌重、肝脏重和体重呈显著或极显著正相关（P<0.05;P<0.01）,胸肌IGFBP-3 mRNA表达量与其胸肌重、肝脏重和体重均呈极显著负相关（P<0.01）。研究结果揭示,IGFBP-3 mRNA在鸡中的表达具有品种、年龄和组织特异性,出雏前肝脏并不是鸡产生IGFBP-3的主要器官,出雏后鸡IGFBP-3可能主要由肝脏合成,肝脏中IGFBP-3 mRNA水平差异是导致两个品种鸡出雏后体重和胸肌重差异的重要因素。     

鸡lmbr1基因外显子16的SNP检测和单倍型分析

外显子16是鸡lmbr1基因最大的外显子,本研究进行了该外显子在丝羽乌骨鸡和白洛克肉鸡间的SNP检测和单倍型分析。研究表明,鸡lmbr1外显子16的PCR-SSCP基因型在两个品种间的分布存在明显差异,测序从24个个体中检测到4个变异位点,其中T32C变异在两个品种间存在明显差异,丝羽乌骨鸡均含有32T(纯合的TT或杂合的TC),白洛克肉鸡在T32C位点都为纯合的CC;单倍型分析从24个个体中检测到5种单倍型,丝羽乌骨鸡和白洛克肉鸡的单倍型存在明显的差异,hap1和hap2是丝羽乌骨鸡的特异性单倍型,hap5是白洛克肉鸡的特异性单倍型,hap3和hap4主要存在于白洛克肉鸡中,在丝羽乌骨鸡中的比例极少。     

卵黄性腹膜炎、鸡白血病对种鸡死亡率、产蛋率影响的初步调查

为了探讨卵黄性腹膜炎和鸡白血病对种鸡死亡率和产蛋率的影响，在2016年1月至2017年4月中旬，对江苏省常州市某种鸡场岭南黄鸡、花鸡（金茅花鸡）、草鸡（金茅草鸡）、黄脚麻鸡4个品种鸡的发病及死亡情况进行临床症状观察及病理剖解；同时记录鸡场每日的鸡死亡数、产蛋数、每日免疫和用药情况，分析不同时期的死亡率和产蛋率，比较不同品种鸡的产蛋率及产蛋高峰期产蛋率与正常蛋鸡产蛋高峰期产蛋率（参考值80%）之间的差异。从死亡鸡的剖解结果来看，腹腔内卵黄凝固黏连在肠道上，输卵管肿大，充满白色或淡黄色干酪样物，初步诊断为卵黄性腹膜炎；肝脏和脾脏肿大，肠系膜或胸壁有肿瘤状物体，初步诊断为鸡白血病。岭南黄鸡产蛋后期的死亡率极显著高于产蛋上升期和高峰期（P<0.01），黄脚麻鸡产蛋后期的死亡率极显著低于产蛋高峰期（P<0.01）；花鸡、草鸡、黄脚麻鸡产蛋高峰期产蛋率平均值均低于60%，与参考值（80%）差异极显著（P<0.01）。综合试验结果，卵黄性腹膜炎和鸡白血病对鸡场影响严重，导致鸡死亡率上升，产蛋率下降；抗应激药和营养药可以起到缓解预防的作用，但无法根治，尚无有效的治疗方法。     

鸡AMPD1基因PCR-SSCP分析与相关性状的研究

5′-磷酸腺苷脱氨酶1(AMPD1)是嘌呤代谢中的一种重要酶类,它的功能是催化AMP(一磷酸腺苷)脱氨,生成肌苷酸(IMP),从而影响肉质风味。试验采用单链构象多态性(PCR-SSCP)技术,以隐性白羽肉鸡、白来航蛋鸡和两个地方品种(北京油鸡、三黄胡须鸡)纯系鸡为试验材料,对AMPD1基因进行SNPs检测和基因类型判别。卡方检验结果表明: 除三黄胡须鸡和隐性白羽肉鸡、北京油鸡和白来航鸡间差异不显著(P>0.05)外,其他各品种间差异极显著(P<0.01)。AMPD1基因多态性与北京油鸡生产和屠体性状(活重、胸肌率、肌苷酸含量等)相关分析结果表明:肌苷酸含量在三种基因型间差异显著(P<0.05)。初步推断AMPD1可能为影响鸡肉中肌苷酸生成的主效基因或与主效基因相连锁。     

Performance and carcass characteristics of Delaware chickens in comparison with broilers

The recent resurgence in the popularity of keeping small flocks of chickens has brought with it an interest in the production characteristics of heritage breeds of chicken. The Delaware breed was developed in the state of Delaware for meat production and is considered a heritage breed because it has long been passed over in favor of the Cornish cross. The definition of a heritage chicken breed is one that physically conforms to the standards of the American Poultry Association, mates naturally, has a long, productive outdoor lifespan, and a slow growth rate. Production information on raising meat Delawares is lacking, as recent research has focused on diet formulation and genetics for broiler production. This study was undertaken to determine the production efficiency of Delawares as compared with broilers in BW, feed intake, FCR, and carcass dressing percentage. Significant differences in BW were noted between broilers and Delawares throughout the study; this was evident even with chick weights. Delawares took 15 wk to reach the same live BW as that of a broiler at 6 wk. The feed intake was greater for the broilers over Delawares during their 6-wk grow-out. The Delawares required twice as much feed to reach the same BW as that of the broiler. Significant differences between the 2 breeds were observed with regard to FCR, the broilers being the more efficient breed. The Delawares had a significantly lower carcass dressing percentage, just under 65%, as compared with broilers, just over 68%. It is hoped that this information will aid producers of niche-market heritage chickens in their decision-making when considering this breed for meat production.     

基于全基因组SNP标记分析中国地方鸡品种的遗传多样性和种群结构

旨在对中国地方鸡品种的遗传多样性与种群结构进行分析。本研究使用Affymetrix Axiom 600K高密度鸡基因分型芯片对来自8个品种的157只地方鸡及233只商品鸡进行基因分型,以品种作为分组来计算各分组的观测杂合度、期望杂合度、次等位基因频率、近交系数及核苷酸多样性分析地方鸡群体的遗传多样性,利用进化树、主成分分析、群体结构、MDS等方法分析鸡群体的群体结构,基于状态同源(IBS)和群体分化系数(Fst)分析种群内部与种群之间的亲缘关系,利用长纯合片段(runs of homozygosity, ROH)估算得到基于ROH的近交系数。结果表明,各群体的观测杂合度均高于期望杂合度,次等位基因频率在0.175～0.236之间,近交系数在0.018～0.205之间,核苷酸多样性在0～6×10^-4之间,进化树与主成分分析表明品种间出现了明显的群体分化,地方鸡群体与商品鸡群的MDS分析发现我国地方鸡与商业肉鸡品种的遗传距离较近;IBS遗传距离在0.092 9～0.319 9之间;各品种成对Fst分析表明,群体间呈现中高分化程度(0.09～0.22);此次分析共得到了...     

地方鸡种与隐性白羽鸡遗传变异的AFLP指纹

利用6对AFLP引物组合对我国12个地方鸡种和引进鸡种隐性白羽鸡进行了遗传检测,统计了每个引物组合在各个品种中检测到的多态性条带和特异性条带,计算了13个鸡种的遗传相似系数和遗传距离,并据此构建了UPGMA聚类关系图,分析了所研究鸡种的遗传关系.结果表明:6对AFLP引物组合在13个鸡种中共检测到290条多态性条带,平均每个引物组合产生48.3奈多态性标记,同时在每个品种群体中还检测到了数量不等的特异性条带,其中寿光鸡和东乡黑鸡最多,为9条,旧院黑鸡、兴义矮脚鸡和隐性白羽鸡最少,为1条.13个鸡种聚为4类,其中隐性白羽鸡单独聚为一类,鸡种间的遗传相似系数及聚类结果与各个鸡种的地理分布、现实状况相吻合,从而表明AFLP指纹用于我国地方鸡种的遗传多态性分析、品种鉴定及品种间亲缘关系分析是可行的.     

一株肾型鸡传染性支气管炎病毒的初步分离鉴定

从哈尔滨市某肉鸡养殖场疑似传染性支气管炎的病死鸡中分离到1株肾型IBV,并对其进行鸡胚矮小化、血凝性、电镜下特征、新城疫干扰试验、致病性等生物学鉴定和N基因的RT-PCR鉴定。结果表明,该病毒分离株在鸡胚上传至第四代(F)4开始出现死亡或侏儒胚;病毒不凝集鸡红细胞;透射电镜下可见多呈球形、直径约80～120nm的病毒粒子,具有冠状病毒的典型形态特点;该病毒可干扰新城疫LaSota株在鸡胚中的增殖;将分离毒第4代尿囊液接种于6日龄雏鸡,7d后开始出现死亡,死亡率高达67%(6/9),病死鸡剖解后可见肾脏明显肿大、苍白,具有传染性支气管炎的典型病变;分离毒第5代尿囊液经N基因特异性RT-PCR获得大小约438bp的目的片断。初步确定所分离病毒为肾型IBV。     

Allele‐specific polymerase chain reaction typing and sequencing of mitochondrial D‐loop region in broiler chickens in Japan

This study aimed to comprehend a feature of single nucleotide polymorphism (SNP) in mitochondrial DNA (mtDNA) mainly of general broiler chickens in Japan. We typed two SNP sites (199C/T and 792A/G) of the D‐loop region in mtDNA by allele‐specific PCR (AS‐PCR) in 359 broiler (182 chunky and 177 cobb) and 506 layer (233 White Leghorn, 140 Barred Plymouth Rock and 133 Rhode Island Red) chickens. The SNP of 199C or 792A by AS‐PCR was observed in the chunky and cobb chickens, and not in the layers. The haplotype 199T/792G was observed in a part of cobb and all layers. By the result of AS‐PCR haplotyping and the broiler brands, the D‐loop region was sequenced in 44 broiler chickens (20 chunky and 24 cobb) and compared with the layers’ sequence data. Among the broiler and layer chickens, 21 SNP sites (including one insertion) and 11 sequence haplotypes were observed. Haplotype variation or correspondence was observed in and between the broiler brands. This study provides important information to establish a chicken meat traceability system by SNP haplotyping of mtDNA in Japan.     

Study on differentiation during embryonic development across selective and ancestral breeds

In order to explore the effect of strain on diverging post‐hatch muscle properties, muscle regulation during embryo development was investigated in selected and unselected breeds. Four broiler strains were used: JingNing (JN) chicken (a Chinese native chicken), HuangYu (HY) broiler, BaiYu (BY) broiler and Hyline layer (commercial crossbred chickens). Results showed that the four breeds had almost the same characteristic during different incubation periods. BY broilers moved more than JN and Hyline layers from Hamburger & Hamilton stage (HH)24 to HH31 (P < 0.05). HY broilers moved more than JN and Hyline layers from HH27 to HH31 (P < 0.01). All the embryos were heavier daily from HH24 to ED18 (P < 0.05); broilers presented greater body weights than JN and hyline layers (P > 0.05); broilers presented smaller fiber diameter than JN chickens before HH31 (P > 0.05). From then on, JN chicken exhibited smaller fiber diameter compared to the broilers (P > 0.05). Western blotting indicated all the breeds had continuous insulin‐like growth factor‐I (IGF‐I) expression, with the highest expression level in broilers from HH19 to HH24 and highest expression level in JN chicks from HH27 to HH31. The results indicated that the diverging growth among breeds was already shown in embryonic stages; the different expression patterns of IGF‐I may be involved in cell proliferation and differentiation.