Comparative pathological studies on domestic geese (Anser anser domestica) and Muscovy ducks (Cairina moschata) experimentally infected with parvovirus strains of goose and Muscovy duck origin

Parvovirus infection of Muscovy ducks caused by a genetically and antigenically distinct virus has been reported from Germany, France, Israel, Hungary, some Asian countries and the USA. The pathological changes include those of degenerative skeletal muscle myopathy and myocarditis, hepatitis, sciatic neuritis and polioencephalomyelitis. In the study presented here, day-old and 3-week-old goslings and Muscovy ducks were infected experimentally with three different parvovirus strains (isolates of D-216/4 from the classical form of Derzsy's disease, D-190/3 from the enteric form of Derzsy's disease, and strain FM from the parvovirus disease of Muscovy ducks). All three parvovirus strains caused severe disease in both day-old and 3-week-old Muscovy ducks but in the goslings only the two strains of goose origin (D-216/4 and D-190/3) caused disease with high (90-100%) mortality when infection was performed at day old. Strain FM (of Muscovy duck origin) did not cause any clinical signs or pathological lesions in the goslings. In the day-old goslings and Muscovy ducks the principal pathological lesions were severe enteritis with necrosis of the epithelial cells (enterocytes) of the mucous membrane and the crypts of Lieberkühn, and the formation of intranuclear inclusion bodies. Other prominent lesions included hepatitis and atrophy (lymphocyte depletion) of the lymphoid organs (bursa of Fabricius, thymus, spleen). In goslings infected with the strain originating from the classical form of Derzsy's disease mild myocarditis was also detected. After infection at three weeks of age, growth retardation, feathering disorders, myocardial lesions (degeneration of cardiac muscle cells, lympho-histiocytic infiltration) and hepatitis were the most prominent lesions in both geese and Muscovy ducks. In addition to the lesions observed in the geese, muscle fibre degeneration, mild sciatic neuritis and polioencephalomyelitis were also observed in the Muscovy ducks infected with any of the three parvovirus strains.     

番鸭细小病毒病病原的血清学检测与PCR鉴定

为了解安徽省番鸭细小病毒病的流行情况,采用酶联免疫吸附试验(ELISA)对该省内部分番鸭群进行鹅细小病毒的血清抗体检测,同时对疑似病鸭进行了病原的PCR检测。结果发现,在被检测的44份血清样本中鹅细小病毒血清抗体阳性率高达34.1%;PCR检测结果显示,所检测的样品中,有2份为鹅细小病毒阳性,1份为番鸭细小病毒阳性,且3份被检样品均来自雏番鸭。该研究结果表明,该省番鸭群中存在鹅细小病毒和番鸭细小病毒感染,应采取有效的预防控制措施。     

不同羽色和性别番鸭屠宰性能及肌肉成分比较研究

研究旨在比较不同羽色及性别番鸭在屠宰性能及肌肉成分上的差别,为选育优良番鸭品种提供依据。试验选取1日龄黑羽番鸭、白羽番鸭及黑白花番鸭公、母共324羽,按羽色、性别分为6个处理,每处理设6个重复,每重复9只鸭,各处理饲喂相同日粮,试验期90d。结果表明：雄性黑羽番鸭屠宰率、全净膛率显著高于雄性白羽及黑白花羽番鸭（P〈0．05）,而雌性黑白花番鸭及白羽番鸭的胸肌率和瘦肉率相近且均显著高于雌性黑羽番鸭（P〈0．05）;各处理番鸭肌肉中汞、镉、砷、铅含量无显著差异（P〉0．05）,且均很微量;各同羽色雄性番鸭肌肉水分、无氮浸出物和粗蛋白质含量均基本略高于其同羽色雌性番鸭,而各处理雌性番鸭肌肉粗脂肪、粗灰分含量则高于其同羽色的雄性番鸭;雄性白羽番鸭和黑白花番鸭肌肉粗蛋白质含量相近且均显著高于雄性黑羽番鸭（P〈0．05）;各同羽色番鸭中基本上肌肉氨基酸含量均以雄性高于雌性,而同性别的番鸭比较,雄性白羽番鸭肌肉中多种氨基酸的含量显著高于雄性黑羽及雄性黑白花羽番鸭（P〉0．05）;同时雌性各羽色番鸭肌肉中多种氨基酸含量呈现出：黑白花番鸭〉黑羽番鸭〉白羽番鸭,但该趋势不显著（P〉0．05）。试验结果表明,雄性黑羽番鸭屠宰性能有一定优势,白羽番鸭肌肉养分和氨基酸含量优势明显。     

番鸭新病——花肝病的研究：Ⅰ．分离毒的致病必及感染途径试验

番鸭花肝的是近年流行的一种新的番鸭疫病，其特征性病变是死亡番鸭的肝、脾、小肠等部位出现灰白色的坏死点，本文自广东省主要疫区分离到几株病毒，这些病毒在番鸭胚上可继代繁殖，其胚液可使番鸭妇病。不同途径感染试验表明该病毒通过肌肉注射、爪垫部注射、口服，同居感染均可使番鸭发病和死亡，并具有典型病变，分离毒不能使半番鸭，本地鸭，鸡发病。     

番鸭细小病毒与鸭圆环病毒二重PCR方法的建立

根据基因库中鸭圆环病毒和番鸭细小病毒的基因序列,分别设计了两对特异性引物,通过对二重PCR扩增条件的优化,研究建立了可同时鉴别检测鸭圆环病毒和番鸭细小病毒的二重PCR方法。用该方法对同一样品中鸭圆环病毒和番鸭细小病毒的模板进行PCR扩增,结果均得到了与实验设计相符的351bp（鸭圆环病毒）和474bp（番鸭细小病毒）的扩增条带,而对鸭Ⅰ型肝炎病毒、鹅细小病毒、鸭副黏病毒、鸭瘟病毒和禽流感病毒等病原体的检测全为阴性。敏感性测定结果表明：该二重PCR技术最低能检出100fg的鸭圆环病毒和番鸭细小病毒DNA模板。研究建立的鸭圆环病毒和番鸭细小病毒的二重PCR方法,具有快速、敏感、特异、定量和重复性好等优点,可用于临床上鸭圆环病毒和番鸭细小病毒感染的检测。     

4个微卫星标记分析6个鸭群体之间的遗传关系

利用4对微卫星引物（AJ272577、AJ272578、AJ272579和AJ272580）对6个鸭群体（绍鸭、番鸭、樱桃谷鸭、北京鸭（Z4、Z1）和奥白星鸭）300只鸭的等位基因频率、群体多态信息含量、有效等位基因数、杂合度和遗传距离进行了检测。结果表明：4个微卫星基因座在6个鸭群体中均存在多态性，可以用于鸭的遗传多样性评估；且基因座AJ272578变异最大，基因座AJ272579变异最小，从不同群体来看，北京鸭Z1的遗传变异最大，奥白星鸭的遗传变异最小。基于Nei氏标准遗传距离，采用UPGMA方法构建了系统发生树，将绍鸭和樱桃谷鸭归为一类，北京鸭Z1、奥白星鸭和北京鸭Z4归为一类，番鸭归为一类。鸭的微卫星基因分型技术为检测品种（群体）之间的遗传关系提供了一个有用的工具。     

Diagnosis of duck plague in waterfowl by polymerase chain reaction

A recently developed polymerase chain reaction (PCR) assay was used for diagnosis of duck plague in waterfowl tissues from past and current cases of waterfowl mortality and to identify duck plague virus in combined cloacal/oral-pharyngeal swab samples from healthy mallards (Anas platyrhynchos) after a disease outbreak. The PCR was able to detect viral DNA from all the individual or pooled tissues assayed from 10 waterfowl, including liver and spleen samples from three Muscovy ducks (Cairina moschata domesticus) that did not yield virus isolates. The strong staining intensity of the PCR products from the waterfowl tissues indicated that large amounts of virus were present, even when virus was not isolated. Duck plague DNA was also detected in a cloacal swab sample from a wood duck (Aix sponsa) carcass submitted for diagnosis. The PCR assay identified duck plague DNA in 13 swab samples that produced virus isolates from carrier mallards sampled in 1981 after a duck plague die-off. The duck plague PCR clearly demonstrated the ability to quickly diagnose duck plague in suspect mortality cases and to detect virus shed by carrier waterfowl.     

3个品种鸭的屠宰性能及肌肉营养成分比较

将番鸭、樱桃谷鸭、高邮鸭饲养到70日龄屠宰。测定屠宰性能,同时取胸肉和腿肉测定营养成分。结果表明:樱桃谷鸭早期生长速度最快;番鸭是3个鸭品种中肉用性能最好的优质肉鸭,樱桃谷鸭的腿肉比例偏小,高邮鸭的胸、腿肌率均未达到优质肉鸭的要求。番鸭鸭肉中水分含量较高,樱桃谷鸭与高邮鸭鸭肉中脂肪含量较高。     

Evidence of Muscovy duck parvovirus in Muscovy ducklings in California

Muscovy duck parvovirus (MDPV) has been demonstrated in tissue samples from one- to four-week-old commercially reared Muscovy ducks that were weak, unable to walk and had a high mortality rate. On postmortem examination, the thigh and leg muscles, and the myocardium were found to be pale, and there was a fibrinous exudate on the capsule of the liver, and ascites. The parvovirus was isolated in embryonated Muscovy duck eggs and visualised by negative stain electron microscopy, detected by polymerase chain reaction (PCR) directly from the tissues, and antibodies to it were detected by immunoelectron microscopy, ELISA and immunofluorescence. In addition, the PCR products obtained that represented 1625 bp (74 per cent) of the capsid vP1 gene, including a hypervariable region between Derzsy's disease virus or goose parvovirus and MDPV, were sequenced and shown to be 100 per cent homologous with the MDPV 89384 reference strain, but only 82.3 per cent homologous with Derzsy's disease virus.     

Differential protein profiles in duck meat during the early postmortem storage period

The present study was designed to investigate proteomic differences in duck breast muscle during the early postmortem storage period. The meat quality was evaluated at 0 hr and 24 hr postmortem at 4°C in Pekin ducks, black Muscovy ducks and Mule ducks. Differentially expressed proteins were detected by two‐dimensional gel electrophoresis (2‐DE) and matrix‐assisted laser desorption ionization‐time‐of‐flight mass spectrometry (MALDI‐TOF/TOF MS) at 0 hr and 24 hr postmortem in the three duck breeds. The results showed that 53 proteins spots were differentially expressed at 0 hr and 24 hr postmortem at 4°C in Pekin ducks, 75 spots in black Muscovy ducks, and 72 spots in Mule ducks. A total of 30 (10 spots for each breed) were selected for identification by mass spectrometry. Seven proteins were identified in Pekin ducks, eight in black Muscovy ducks and seven in Mule ducks. Moreover, the above results obtained by 2‐DE and MALDI‐TOF/TOF MS were confirmed by western blotting. To our knowledge, this study is the first to provide insights into the protein profiles of ducks during postmortem storage and provides a better understanding of the biochemical processes that contribute to duck meat quality.     

白色羽毛半番鸭选育的研究

从正交，反交，轮交和侧交揭示产生半番鸭白色羽毛起主导作用的是家鸭。不同基因型家鸭产生白羽半番鸭频率是不同的，同一品种母家鸭个体间产生白羽半番鸭亦不同，母爱鸭生产白羽率高的个体，用不同公番鸭交配，其Ｆ１白率仍然是高的，估测ｈ＾２为０．６６３８。经５个世代亲本选择，半番鸭白羽率达９３．４９％，１０周龄活重２７８６克。     

Isolation and characterization of a subtype C avian metapneumovirus circulating in Muscovy ducks in China

Subtype C avian metapneumovirus (aMPV-C), is an important pathogen that can cause egg-drop and acute respiratory diseases in poultry. To date, aMPV-C infection has not been documented in Muscovy ducks in China. Here, we isolated and characterized an aMPV-C, designated S-01, which has caused severe respiratory disease and noticeable egg drop in Muscovy duck flocks in south China since 2010. Electron microscopy showed that the isolate was an enveloped virus exhibiting multiple morphologies with a diameter of 20–500 nm. The S-01 strain was able to produce a typical cytopathic effect (CPE) on Vero cells and cause death in 10- to 11-day-old Muscovy duck embryos. In vivo infection of layer Muscovy ducks with the isolate resulted in typical clinical signs and pathological lesions similar to those seen in the original infected cases. We report the first complete genomic sequence of aMPV-C from Muscovy ducks. A phylogenetic analysis strongly suggested that the S-01 virus belongs to the aMPV-C family, sharing 92.3%-94.3% of nucleotide identity with that of aMPV-C, and was most closely related to the aMPV-C strains isolated from Muscovy ducks in France. The deduced eight main proteins (N, P, M, F, M2, SH, G and L) of the novel isolate shared higher identity with hMPV than with other aMPV (subtypes A, B and D). S-01 could bind a monoclonal antibody against the F protein of hMPV. Together, our results indicate that subtype-C aMPV has been circulating in Muscovy duck flocks in South China, and it is urgent for companies to develop new vaccines to control the spread of the virus in China.     

ELISA检测三种家鸭试验性感染潜鸭艾美耳球虫的血清抗体

将潜鸭艾美耳球虫孢子化卵爱清洁、纯化，捣碎滤过制成可溶性抗原，用于ＥＬＩＳＡ检测番鸭、北京鸭和二者杂交种骡鸭试验性感染潜鸭艾美耳球虫后血清中抗体的变化。试验鸭于１１日龄每只口服接种孢子化卵囊７．５×１０４个，接种感染后第３天血清抗体的ＯＤ值开始上升，番鸭和骡鸭感染后第１０天血清抗体达峰值，而北京鸭的峰值出现较晚，在感染后第１７天。番鸭和骡鸭在试验期间血清抗体ＯＤ值有两个峰值：第２峰值番鸭出现在感染后第１７天，骡鸭在感染后第２０天。３种鸭血清ＩｇＧ的变化曲线与血清Ｉｇｓ的相近似，表明在家鸭感染球虫后血清ＩｇＧ在血清抗体Ｉｇｓ中占主要地位。同时各组的不感染健康鸭血清免疫球蛋白随日龄增大显缓慢增长，但明显低于接种感染鸭。     

Effects of alfalfa meal on carcase quality and fat metabolism of Muscovy ducks

1. The effects of alfalfa meal on carcase quality and fat metabolism of Muscovy duck were evaluated. The objective of this research was to establish whether alfalfa meal can reduce fat content and improve carcase quality of Muscovy duck. Animal products with a high fat content present a risk factor for many diseases. Reducing fat content in poultry products is an important goal for the poultry industry.

2. A total of 240 14-d-old white Muscovy ducks were selected and randomly allocated to 1 of 4 dietary treatments containing 0, 3, 6, and 9% of alfalfa meal for 5 weeks. Growth performances were recorded and carcase characteristics and lipid parameters were analysed.

3. Results showed that 3, 6, and 9% alfalfa meal in diet had no significant effects on growth performance of Muscovy ducks from 14 to 49?d of age. Ducks given 3, 6, and 9% alfalfa meal had significantly higher dressing percentage and lower abdominal fat percentage compared with those given no alfalfa meal. Ducks given 9% alfalfa meal had higher breast meat percentage compared with those given no alfalfa meal. The concentrations of triglyceride, total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL) and free fatty acid in serum of ducks fed on alfalfa meal decreased. Alfalfa meal in the diet decreased abdominal fat percentage and improved carcase traits of Muscovy duck.

4. The study showed that dietary alfalfa meal decreased abdominal fat percentage and improved carcase traits, without an adverse effect on performance.     

鸭出血症病毒间接ELISA检测方法的建立与应用

为了建立快速检测鸭出血症病毒(DHDV)的血清学方法,本试验利用浓缩纯化的DHDV作为包被抗原,建立了检测DHDV血清抗体的间接ELISA方法,并对各种检测条件进行了优化。试验结果表明,抗原最佳稀释浓度为7.06 μg/孔;最佳包被条件为37 ℃ 1 h后,4 ℃包被过夜;待检血清的最佳稀释倍数为1:25。在优化条件下,阴阳性临界值判定标准为0.44。建立的ELISA方法对鸭瘟病毒、鸭病毒性肝炎病毒、雏番鸭细小病毒和番鸭呼肠孤病毒阳性血清均无交叉反应,结果表明该方法具有良好的特异性。批内和批间重复性试验的最大变异系数分别为0.0221、0.0032,显示该方法具有很好的稳定性,与血清中和试验的符合率为100%。该方法快速、简单、特异性好、重复性好,可用于大批量监测鸭群DHDV血清抗体感染情况。     

Effect of species,breed and route of virus inoculation on the pathogenicity of H5N1 highly pathogenic influenza (HPAI) viruses in domestic ducks

H5N1 highly pathogenic avian influenza (HPAI) viruses continue to be a threat to poultry in many regions of the world. Domestic ducks have been recognized as one of the primary factors in the spread of H5N1 HPAI. In this study we examined the pathogenicity of H5N1 HPAI viruses in different species and breeds of domestic ducks and the effect of route of virus inoculation on the outcome of infection. We determined that the pathogenicity of H5N1 HPAI viruses varies between the two common farmed duck species, with Muscovy ducks (Cairina moschata) presenting more severe disease than various breeds of Anas platyrhynchos var. domestica ducks including Pekin, Mallard-type, Black Runners, Rouen, and Khaki Campbell ducks. We also found that Pekin and Muscovy ducks inoculated with two H5N1 HPAI viruses of different virulence, given by any one of three routes (intranasal, intracloacal, or intraocular), became infected with the viruses. Regardless of the route of inoculation, the outcome of infection was similar for each species but depended on the virulence of the virus used. Muscovy ducks showed more severe clinical signs and higher mortality than the Pekin ducks. In conclusion, domestic ducks are susceptible to H5N1 HPAI virus infection by different routes of exposure, but the presentation of the disease varied by virus strain and duck species. This information helps support the planning and implementation of H5N1 HPAI surveillance and control measures in countries with large domestic duck populations.     

鸭副黏病毒和鸭圆环病毒二重荧光定量PCR检测方法的建立

根据鸭副黏病毒(DPMV)和鸭圆环病毒(DuCV)保守基因序列,设计了2对针对鸭副黏病毒和鸭圆环病毒的特异性引物和2条不同荧光基团标记的TaqMan探针,建立了鸭副黏病毒和鸭圆环病毒的二重荧光定量PCR检测方法。该方法敏感性好,对鸭副黏病毒和鸭圆环病毒的检测敏感性分别达到160和140个拷贝数;该方法特异性强,对鸭肝炎病毒、番鸭细小病毒、鸭瘟病毒和H9型禽流感病毒等病原体的检测全为阴性;应用该方法对118份临床病料进行检测,结果检出鸭副黏病毒和鸭圆环病毒阳性感染率分别为0.85%和8.47%,无混合感染。本试验建立的二重荧光定量PCR具有快速、特异、敏感和重复性好等优点,适用于鸭副黏病毒和鸭圆环病毒的快速诊断和监测。     

鸭新城疫病毒和鸭圆环病毒二重PCR检测方法的建立

本研究根据GenBank中鸭新城疫病毒(NDV)的F基因和鸭圆环病毒(DuCV)的V1/rep基因的保守序列,各设计一对特异性引物,并对二重PCR的扩增条件进行优化,建立了鸭NDV和DuCV的二重PCR检测方法。对混合样品进行扩增,得到2条大小为493bp(鸭NDV)和218bp(DuCV)的特异性条带,与预扩增片段相符。而对番鸭细小病毒、鸭瘟病毒、鸭肝炎病毒、鸭源小鹅瘟病毒、鸭H9亚型流感病毒、鸭疫里氏杆菌、大肠杆菌、禽多杀性巴氏杆菌等病原检测,结果为阴性。该方法的敏感性试验表明,鸭NDV的核酸最小量为40fg,DuCV为20fg。     

发酵脐橙粕对番鸭肠道形态结构、肠黏膜免疫功能和微生物多样性的影响

【目的】通过研究发酵脐橙粕对番鸭肠道形态结构、肠黏膜免疫功能和微生物多样性的影响,探究发酵脐橙粕用于番鸭节粮养殖的可行性。【方法】选取健康、体重为(267.33±9.50)g的180只16日龄番鸭,随机分成2组(每组公母各半),每组6个重复,每个重复15只,对照组饲喂基础饲粮,试验组饲喂含有100 g/kg发酵脐橙粕的基础饲粮,预饲期7 d,正式试验期48 d。试验结束后,采集番鸭十二指肠组织样品和盲肠内容物。通过HE染色法和免疫组化法检测十二指肠肠道形态学指标和肠黏膜免疫功能指标;采用高通量测序技术对盲肠内容物的微生物16S rDNA进行测序,分析盲肠微生物多样性变化情况。【结果】(1)与对照组相比,100 g/kg发酵脐橙粕可极显著提高番鸭十二指肠的绒毛高度(P<0.01),显著提高绒毛表面积和上皮内淋巴细胞阳性率(P<0.05)。(2)显著物种差异分析结果显示,与对照组相比,饲喂100 g/kg发酵脐橙粕饲粮极显著抑制了番鸭盲肠脱铁杆菌门、厌氧菌科和无胆甾原体等有害菌丰度(P<0.01),极显著提高了黄杆菌属、螺杆菌属和巨单胞菌属等有益菌的丰度(P<0.0...     

半番鸭及其亲本生长曲线拟合与杂种优势分析

实验测定了樱桃谷鸭、白羽番鸭、苏牧麻鸭、白羽番鸭♂×樱桃谷鸭♀(樱番鸭)、白羽番鸭♂×苏牧麻鸭♀(苏番鸭)早期体重数据,发现樱番鸭杂种优势率为12.8%,苏番鸭为22.04%。用Logistic、Von Bertalanffy和Gompertz3种非线性生长模型拟合其生长曲线,通过比较拟合优度、复相关指数和进行适合性χ2检验,发现Gompertz模型拟合效果最好。比较5组鸭Gompertz模型拟合参数,结果表明:在亲本鸭组中白羽番鸭初始重较樱桃谷鸭和苏牧麻鸭高,初始生长速度、最大周增重较这2个亲本组低,拐点时间也比其晚。2个杂交组最大周增重、成熟速度、极限体重、拐点体重、初始重和拐点时间都有很大提高,存在明显的杂种优势。