鸡禽霍乱疾病流行病学特点及防控措施

鸡养殖中禽霍乱疾病的出现主要是由于多杀性巴氏杆菌感染的一种传染性疾病,主要会导致鸡只出现急性败血症和机体炎症反应等,慢性型感染会导致鸡只出现皮下及机体内脏器官、关节等的化脓性炎症反应。禽霍乱疾病在鸡养殖全年均会出现,尤其是在气温变化较大的时期疾病爆发的可能性更高。禽霍乱疾病在急性爆发的情况下病死率相对较高,同时短期内即会出现死亡的情况,难以进行有效的治疗,易导致鸡养殖户出现严重的经济损失。该文主要对鸡禽霍乱疾病的流行病学特点、临床症状及相关的防治措施进行论述。     

菌毒康对禽霍乱的防治试验

用纯中药制剂菌毒康对鸡人工感染禽多杀巴氏杆菌强毒株Ｃ４８－１进行了预防和治疗试验。结果表明,攻毒组１０羽鸡于３ｄ内全部死亡;治疗Ⅰ组１０羽鸡存活１羽,存活率１０％;治疗Ⅱ组１０羽鸡全部死亡;预防Ⅰ组１０羽鸡存活８羽,存活率８０％;预防Ⅱ组１０羽鸡存活７羽,存活率７０％;同舍感染组死亡率１００％。由此可见,菌毒康对禽霍乱强毒感染的治疗效果不明显。但对禽霍乱强毒感染有一定的预防作用。     

甘露寡糖对肉鸡鸟类禽霍乱的病理改善作用

禽霍乱(FC,禽巴氏杆菌病,禽出血性败血病)是一种对家禽和野生鸟类易感的传染性疾病.本研究是通过在肉鸡上实验室接种多杀性巴氏杆菌引起禽霍乱严重程度确定饲喂益生素甘露寡糖(MOS)的作用效果.试验选用48只健康,相同日龄和性别白来航雏鸡作为研究对象.试验分为两组并在标准饲养和管理条件下进行,试验组Ⅱ额外添加益生素MOS.在第28天试验鸡只通过灌服感染1 mL/kg体重禽霍乱巴氏杆菌.此后,观察记录感染情况并在感染后12、36和48 h候处死.其中,补充MOS的试验组Ⅱ无死亡.在三个时间点检测血液中细菌数量,发现补充MOS试验组细菌数量要少得多.观察两试验组鸡只组织,发现在肺、肝、脾、心脏和小肠组织发生显著性变化.但是,给予MOS补充试验组在三个时间点病变较轻微.该研究表明,补充益生素MOS试验组在三个时间点上降低试验鸡感染程度.这主要表现在改善血液生化指标,降低机体血液中细菌含量,缓解各阶段和各组织在肉眼和显微镜下病变程度.结论:MOS补充剂可降低禽霍乱对内鸡的危害.     

万年青和玉槐姜治疗禽霍乱试验

以禽霍乱C48—1菌株对鸡攻毒8个菌,攻毒后6小时肌注槐姜液,保护率75％。效果和肌注青霉素同,对照鸡全部死亡。本文并介绍玉槐姜的特征、产地和加工方法。目前,虽有禽霍乱菌苗预防本病,也有抗生素、如青霉素、链霉素和磺胺类等药物治疗。但药物较贵,所以笔者试选中草药玉槐姜与万年青对人工感染禽霍乱强毒的鸡作试验治疗,取到可喜的结果。报告如下:     

不同佐剂对禽霍乱弱毒苗在鸡体内居留时间的影响

以不同佐剂处理的禽霍乱弱毒活菌液,胸肌接种鸡后,不同时间内剖杀试验鸡,分别采集注射部位、肝、脾、肾、肺、胸腺、胰、脑、法氏囊和心血等组织材料作巴氏杆菌分离。结果表明:(1)禽霍乱活菌在鸡体内器官居留时间十分短暂,在肝、脾、肾、肺居留时间最长只有1—2天;(2)不同时间剖杀试验鸡均末能从胸腺、胰、脑、法氏囊和心血等材料中分离到接种菌;(3)不同佐剂处理的活菌液在注射居留时间,以油佐剂的6—8天为最长,其次是铝胶佐剂的5天,不加任何佐剂的马丁汤稀释菌液在局部居留时间最短,只有1—2天。     

规模化土鸡养殖场主要疫病流行病学调查

为了解2012~2014年信阳地区土鸡主要疫病流行情况,对36个规模化土鸡养殖场的3 782个病鸡样本进行实验室检测和分析。结果表明:雏鸡阶段主要流行疾病有沙门菌病、支原体感染、新城疫、鸡传染性法氏囊病、球虫病和大肠杆菌病;青年鸡的主要疾病有寄生虫病、支原体感染、大肠杆菌病、禽霍乱、鸡传染性鼻炎、新城疫、禽流感、禽白血病和鸡传染性支气管炎;成年鸡的主要疾病有寄生虫病、支原体感染、大肠杆菌病、禽霍乱、鸡传染性鼻炎、新城疫、禽流感和鸡传染性支气管炎。各阶段多病原混合感染普遍存在。     

26日龄雏鸡禽霍乱和球虫病混合感染的诊治

2003年6月个体养鸡户于某从某孵化站购进雏鸡1000只，当饲养到26日龄时，鸡群中有部分鸡出现了食欲废绝，排黄色或淡绿色粪便、有时还排血便等症状，两周内就死亡498只，死亡率达49．8％，确诊为禽霍乱和球虫病混合感染。     

用当地禽霍乱死禽组织灭活苗防治本病效果好

通常情况下发生禽霍乱的禽（鸡、鸭、鹅等）群，开始只有少数突然死亡的病例，用敏感药物（如氯霉素等）治疗２～３ｄ后即可制止死亡，但停药不当又会复发，并继续出现零星死亡，经济上造成很大损失。再者，巴氏杆菌的血清型很多，不同血清型菌株的禽霍乱疫苗间，往往不能...     

治疗禽霍乱的较佳用药方案

禽霍乱又称禽出败或禽巴氏杆菌病,常呈散发性或地方性流行发生,鸡、火鸡、鸭和鹅均能被感染。其病原体是多杀性巴氏杆菌。鸡在达到性成熟时对禽霍乱特别易感,常表现为最急性和急性败血症。病鸡死亡快、病死率很高,前驱症状不明显或症状仅发生于死亡前数小时。症状为流涎、冠发绀和急剧下痢。剖检可见粘膜、浆膜有出血点或出血斑,特征病变是肝表面有大量针尖大的灰白色坏死灶。慢性病例以肉髯水肿和关     

观鸡粪辨鸡病

１水样下痢鸡中毒、禽伤寒、禽霍乱、新城疫、溃疡性肠炎和传染性法氏囊病均可发生。鸡中毒后仅出现水样下痢；禽伤寒鸡腹泻严重，拉出的鸡粪呈黄绿色，粘在肛门周围的羽毛上；禽霍乱鸡从水样下痢开始，继而出现白色粘液性下痢，以后由白色转为绿色，其中含有粘稠液的淡...     

维生素D3对丝毛乌骨鸡组织中β-防御素基因的表达调控

本试验旨在研究不同水平维生素D3对丝毛乌骨鸡组织中β-防御素(AVBDs)基因表达的调控.采用实时荧光定量PCR方法检测饲喂不同水平(800、1 600、3 200和6 400 IU/kg)维生素D3对丝毛乌骨鸡胸腺、十二指肠、空肠、回肠、盲肠和法氏囊中3个β-防御素(AVBD-1、AVBD-5和GAL-1)基因表达水平的影响.结果表明:3个β-防御素基因在6个组织中均有表达,其中乌骨鸡AVBD-1和GAL-1基因的最高表达水平都在采食了3 200 IU/kg维生素D3时的空肠;AVBD-5基因的最高表达水平在采食了1 600 IU/kg维生素D3时的十二指肠;在依次采食维生素D3800、1 600、3 200和6 400 IU/kg的乌骨鸡组织中,3个β-防御素基因都存在先升后降的表达趋势.结果表明,β-防御素基因在同一组织的表达水平与维生素D3饲喂水平存在剂量关系,适宜的维生素D3饲喂水平能上调这3个β-防御素基因在乌骨鸡组织中的表达量.     

禽霍乱+大肠杆菌病二联蜂胶灭活疫苗与油佐剂疫苗注射部位的动态病理组织学比较观察

用禽霍乱+大肠杆菌二联蜂胶灭活疫苗和油佐剂疫苗分别胸肌注射免疫肉鸡,分别于免疫后7d、14d和28d剖杀,取注射部位的肌肉组织,常规石蜡包埋切片观察。结果为,蜂胶疫苗免疫组免疫后7d时,肌纤维轻度水肿,纤维间有大量淋巴细胞和巨噬细胞的浸润,巨噬细胞吞噬有蜂胶颗粒,14d时肌纤维则恢复正常;油苗注射组免疫后,7d时肌肉中度水肿,其间有大量油乳状疫苗残留,镜检可见肌纤维断裂、坏死,其间有较多较大的油囊,囊壁由大量增生的成纤维细胞、异嗜性粒细胞、巨噬细胞、小血管及淋巴样细胞组成,细胞增生持续存在到28d,最后形成肉芽肿结构。研究结果表明,蜂胶疫苗免疫后对局部组织学影响明显小于油苗注射组。     

Two fiber genes of nearly equal lengths are a common and distinctive feature of Fowl adenovirus C members

The complete genome or the genome region containing the two fiber genes of two reference strains and one field isolate representing both serotypes of Fowl adenovirus C were sequenced. Two fiber genes were revealed in the genomes of all three isolates. Fiber-1 and fiber-2 genes of several Fowl adenovirus C isolates were sequenced as well. Both serotypes 4 and 10 have two fiber genes. The genome region containing the fiber gene was also sequenced for the reference strain of Fowl adenovirus B. Just one fiber gene was revealed in this strain. Predicted amino acid sequences were compared to already published fiber sequences of different adenovirus isolates and one amino acid substitution within fiber-2 was detected in all of the Fowl adenovirus C isolates that were isolated from chickens with hepatitis-hydropericardium syndrome in comparison to apathogenic isolates. Phylogenetic analyses provided insights about the evolution of fiber genes in avian adenoviruses and their genetic relationships.     

Fate and uptake of soluble and particulate antigens in the preparturient bovine mammary gland

Pregnant heifers were infused intramammarily with ovalbumin in one quarter and killed S. uberis in another quarter. The animals were slaughtered at time intervals after infusion, and tissues were collected from different parts of the gland and from the local lymph nodes. Ovalbumin and bacteria reached the lymph nodes as early as 1 and 3 h after infusion respectively. Ovalbumin was also present in blood 5-10 min after infusion and in non-infused quarters. Both ovalbumin and bacteria were phagocytosed by the epithelium of the mammary gland. However, bacteria were seen in the tissues in small numbers at all stages after infusion. Larger numbers were phagocytosed by neutrophils in the lumen of ducts, 18 h after infusion. Phagocytosis of both ovalbumin and bacteria was not present in the connective tissue of the gland. The results indicate increased permeability of the preparturient gland to soluble proteins, but limited uptake of bacteria. Furthermore, a mechanism of transfer of antigens among quarters has been suggested.     

重组减毒沙门菌在雏鸡体内的感染状况研究

为了检测能够表达传染性法氏囊病毒VP2蛋白的重组沙门菌在雏鸡体内主要组织和器官的感染情况,分别用亲本菌株和重组沙门菌免疫雏鸡,免疫后24~216 h每隔24 h对雏鸡的盲肠、血液、肝脏、脾脏、法氏囊中的细菌数量进行分析。结果显示:雏鸡接种重组减毒沙门菌后,其在血液中的数量不断升高并在96 h达到峰值,在脾脏中的数量不断升高并在120 h左右达到峰值,在肝脏、法氏囊中的数量不断升高并在168 h达到峰值,在盲肠中,细菌数量在不断升高并在72 h达到峰值;达到峰值后细菌数量逐渐下降。亲本菌株和重组菌株在相应组织器官中的数量变化趋势一致,但是亲本菌株的数量始终高于重组菌株。结果表明:重组菌株能在雏鸡体内生长定植,能为诱导雏鸡机体产生保护性免疫应答奠定重要基础,有望作为预防传染性法氏囊病毒的口服疫苗。     

猪源乳酸杆菌对仔猪肠道微生物的影响

从猪的新鲜粪便中培养分离获得的三株乳酸杆菌对常见的病原性菌大肠杆菌、猪霍乱沙门氏菌和金黄色葡萄球菌具有一定的抑菌作用。动物接种试验证明,试验分离获得的猪源乳酸杆菌饲喂动物安全,符合益生菌的条件,可以作为益生菌添加到饲料中。在试验中发现,猪源乳酸杆菌和EM菌都有促进仔猪生长发育、提高生产性能、降低发病率和死亡率的作用。在调整仔猪肠道菌群方面:试验各组效果较对照组差异均显著<0.05)。试验二组的效果最好:在增加乳酸杆菌方面,比试验一组高18.5%,比试验四组高12.5%;在减少大肠杆菌方面,比试验二组高6.25%,比试验四组高6.25%;在增加肠道细菌总数方面,比试验一组高37.5%,比试验四组高37.5%。所以,本试验从猪体内获得的乳酸杆菌安全性良好,对改善仔猪肠道环境具有一定的作用。     

Histopathology of experimental plague in cats

Formalin-fixed paraffin-embedded archival tissues of seven adult cats of both sexes that died after being experimentally infected with Yersinia pestis were examined light microscopically to characterize the lesions. The cats were exposed in two groups using two routes of infection: ingestion of Y. pestis-infected rodent or a subcutaneous injection of Y. pestis to simulate a flea bite. Immunohistochemistry was performed on tissues from all organ systems from a representative cat from each group to determine the distribution of Y. pestis bacilli during infection. In all seven cats, bubonic plague lesions were seen. The lesions of pneumonic plague were present in two cats. Septicemic plague was confirmed in all seven cats by bacteriologic culture. Aggregations of bacteria were seen in lymphoid tissue in all cats and in lung tissues from the two cats with pneumonic plague. The most consistent histologic finding was necrosuppurative inflammation in the lymph nodes. Invariably, Y. pestis bacteria were present in large numbers at affected sites. Orally infected cats had more numerous lesions in the lymph nodes of the head and neck regions. These experimentally induced cases of feline plague document that cats are unique among carnivores in exhibiting bubonic, pneumonic, and septicemic plague following exposure to Y. pestis. The lesions of the orally infected cats were consistent with those previously described for naturally occurring Y. pestis infections in cats and corroborate the contention that cats most commonly contract plague by eating Y. pestis-infected rodents and not via flea bite. The histopathology of Y. pestis disease in these cats is comparable to that described for human plague.     

Granulocyte responses to experimental injection of live and formalin-killed bacteria in carp (Cyprinus carpio)

The objective of the study was to investigate the dynamics of changes in number of granulocytes in bacterial infections of carp (Cyprinus carpio). Carp were inoculated with non-pathogenic or pathogenic bacteria and changes in type I (neutrophils) and type II granulocyte (basophils/eosinophils) counts in kidney, circulating blood and peritoneal cavity were assessed. After the injection of non-pathogenic bacteria (Escherichia coli), the number of type I and II cells in blood increased after 6-12h, but returned to the control level after 24-48 h. In contrast, after the injection of pathogenic bacteria (Aeromonas hydrophila), the number of type I cells initially increased followed by an increase in the number of type II cells. The peak counts of type I and II cells were at 12 and 24h after the injection, respectively. When the fish were given serial-injections of formalin-killed bacteria at 12-h intervals, the type II cells also predominantly increased and remained at high levels, following the peak count of type I cells.     

Distribution of neomycin in bull calves after intramuscular injection

Neomycin sulfate was injected intramuscularly in calves. Blood and tissue samples were taken at zero, one, two, four, six, eight and 24 hours after administration. The tissues with high levels (greater than 10 μg/g) of drug at the one hour period were kidney cortex and medulla, urine, blood serum and the injection site. By 24 hours after administration only the kidney cortex and urine had high levels of neomycin. The drug could not be detected in any brain tissues and very small amounts (less than 1 μg/g) were present in the bile, thymus and vitreous humor. Levels greater than 5 μg/g were present in lung tissues for less than four hours but were greater than 2 μg/g for more than 24 hours.

The mean level in the injection site was greater than 700 μg/g at one hour but only trace amounts were found at 24 hours.

On the basis of the tissue drug concentration intramuscularly administered neomycin was suggested as therapeutically useful for respiratory and urinary tract infections caused by susceptible bacteria.

     

Effects of Observed Incubation Behavior on Egg Production in Laying Hens of a Commercial Chicken Breed and Detection of Single-Nucleotide Polymorphisms Associated with the Incubation Behavior

Upon contact with laid eggs, avians initiate incubation behavior and stop laying additional eggs. This phenomenon suggests that the productivity of laying hens in free-range facilities may decrease because of frequent contact with laid eggs. Here, we examined whether hens of a commercial breed exhibit incubation behavior in a free-range facility and whether egg productivity subsequently decreases. One-hour observations were performed twice weekly for 3 weeks, during which 9 of 129 hens (7.0%) exhibited incubation behavior (i.e., sitting on eggs) in the free-range facility and were defined as incubating hens. During 4 d of continuous behavioral observation, incubating and non-incubating hens laid the same number of eggs statistically (4.6 and 3.6, on average, respectively); however, incubating hens spent significantly more time on average incubating the eggs (2071.9 min) than did the non-incubating hens (20.9 min; P<0.05), indicating a clear behavioral difference. Subsequently, the incubation behavior and egg productivity of incubating hens and a Silkie Fowl breed hen, which is known to exhibit typical incubation behavior and cessation of laying, were continuously compared for 27 d. The average minutes spent incubating eggs during the observation period increased in both the incubating hens and Silkie Fowl hen and the total time was almost the same (18,088.5 and 23,092 min, respectively). However, the Silkie Fowl hen stopped laying on day 17 after laying 17 eggs, whereas the incubating hens continued laying throughout the observation period. Incubating hens laid an average of 24.5 eggs, indicating that some hens (at least those of the commercial breed used in our study) can continue laying while exhibiting incubation behavior. A single-nucleotide polymorphism associated with incubation behavior was detected on chromosome 4 through genome-wide association analysis.