规模猪场母猪繁殖障碍综合征的病因调查   总被引：3，自引：0，他引：3  

刘道新  谈志祥  邱伯根  邱立新  鲁杏华  任风梅  邓国强 《中国动物检疫》2003,20(12):25-27

作者采用9套试剂盒，检测了7种能引起猪繁殖障碍综合征的传染病，对来自有繁殖障碍症状的305场次进行猪瘟(HC)抗原检测，并对包括这305场次在内的978个猪场(次)病例的6346份血清样品及52698份田间血清样品进行HC、猪繁殖与呼吸综合征(PRRS)、伪狂犬病(PR)、日本乙型脑炎(JE)、细小病毒感染(DPV)、猪衣原体病(Chla)、布鲁氏菌病(Bruc)等7种传染病的抗体检测。结果表明，在有繁殖障碍症状的猪场，HC抗原检出率高达61．97％，并且在不使用疫苗的情况下，PR3RS、PR、JE、Chla和PPV的抗体阳性场分别为49．42％、34．29％、12．72％、31．71％、和48．08％。HC和：PR交叉感染率达23．81％；HC和：PRRS交叉感染率为9．52％，PR和PRRS交叉感染率高达59．65％；另外JE、PPV也同HC、PR、PRRS存在部分交叉感染。不使用疫苗的田间血清样品的PRRS、PR的抗体阳性率也高。HC与PRRS．PR、Chla、JE和PPV中的一种或几种混合感染可能是引起繁殖障碍造成严重损失的主要原因。加强综合防制，优化免疫程序、把握引种关、加强生物安全措施是防制猪繁殖障碍综合征的关键。  相似文献   

系统耦合与荒漠─绿洲草地农业系统─—以祁连山一临泽剖面为例   总被引：7，自引：0，他引：7  

任继周  万长贵 《草业学报》1994,(3)

生态系统内部自由能的积累，使系统失去平衡并趋于同其它生态系统结合，自由能驱使两个或两个以上的生态系统或亚生态系统，通过会聚，超循环和耦合而联合，从而形成具有特殊结构一功能的更高一级的新系统。系统耦合可以多途径解放生态系统中的自由能而增加农业生态系统的生产力，亦即从催化潜势，位差潜势，多稳定潜势及管理潜势中取得能输出。上述过程可作用于农业系统中的四个子系统，这四个子系统各有自己的产品：前植物生产，植物生产，动物生产，外生物生产，从而大幅度提高其生产力。在荒漠─绿洲草地农业生态系统中，本文分别计量了各个子系统的能流单位及其流程，证明它的子系统也可以成功的发生系统耦合，其中绿洲子系统应居关键地位。  相似文献   

Coagulopathic Effects and Therapy of Brodifacoum Toxicosis in Dogs     

Benny J. Woody DVM  MS    Michael J. Murphy DVM  PhD    AIlen C. Ray PhD  Robert A. Green DVM  PhD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1992,6(1):23-28

The clinical signs and laboratory changes of brodifacoum (BDF) intoxicated dogs and their response to vitamin K1 treatment were examined. Brodifacoum, a second-generation anticoagulant rodenticide, was fed to four dogs for 3 consecutive days producing a cumulative dose of 1.1 mg BDF/kg body weight. Clinical observations of the animals were made daily throughout the study. Monitored laboratory parameters included: one-stage prothrombin time (OSPT), activated partial thromboplastin time (APTT), activated coagulation time (ACT), complete blood counts, thrombocyte counts, and serum chemistry values. Response to vitamin K1 therapy was evaluated clinically and by laboratory tests. Serum BDF concentrations were monitored. Inappetence and hemorrhagic tendencies were exhibited by day 5 postrodenticide exposure. One-stage prothrombin time, APTT, and ACT were 25% greater than time zero values at 24, 24, and 72 hours postdosing, respectively. All laboratory parameters returned to normal within 48 hours of initiating vitamin K1 therapy (0.83 mg/kg orally, TID for 5 days). Serum brodifacoum concentrations were highest (1065-1215 ng/mL) during the 3 days after BDF dosing and were detectable (3.0-7.5 ng/mL) until day 24 postexposure. A mean BDF elimination half-life of 6 +/- 4 days was observed.  相似文献   

Predicting across scales comments of the guest editors of Landscape Ecology     

Virginia H. Dale  Robert H. Gardner  Monica G. Turner 《Landscape Ecology》1989,3(3-4):147-151

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Presentation of postweaning Escherichia coli diarrhea in southern Ontario, prevalence of hemolytic E. coli serogroups involved, and their antimicrobial resistance patterns   总被引：1，自引：0，他引：1       下载免费PDF全文

Rocio Amezcua  Robert M. Friendship  Catherine E. Dewey  Carlton Gyles    John M. Fairbrother 《Canadian journal of veterinary research》2002,66(2):73-78

Post-weaning Escherichia coli diarrhea (PWECD) in Ontario was investigated using a case-control study involving 50 Ontario nurseries. The clinical signs and the impact on productive parameters were determined by means of a producer survey. The hemolytic E. coli serogroups involved in PWECD (O149:K91:K88) were examined in this study. Based on a polymerase chain reaction test, the hemolytic E. coli from 82% of the case herds were positive for 3 enterotoxins (STa, STb, and LT), those from 12% of the case herds were positive for STb and LT only, and those from one herd (6%) were positive for 3 enterotoxins, as well as for verotoxin and F18 pili. The E. coli involved in disease were resistant to multiple antibiotics. Case farms commonly used a wide variety of antibiotics either in the feed or water, or as injectable drugs. The most common antibiotic used to treat PWECD on the study farms was apramycin, but evidence of resistance to this antibiotic was noted. The PWECD problem was commonly seen within a week of weaning but onset of diarrhea was reported as late as the grower-finisher stage. Growth rate was poorer in case herds and mortality was higher than in control herds, demonstrating that PWECD is an economically important disease in Ontario.  相似文献   

观花乔木树种在沈阳街路推广与应用   总被引：1，自引：0，他引：1  

任全伟 《中国林副特产》2006,(5):86-89

通过对沈阳市街路栽植的观花乔木的现状分析,确定了观花乔木的引种与筛选原则,对初选出的近30种观花乔木进行了各种观测试验。基本摸清了这些观花乔木的生物学特性和生态习性;通过应用栽培试验,筛选出栾树、香花槐、红肉苹果、暴马丁香等26种优良观花乔木树种;列出了适合沈阳街路栽植的观花乔木树种名录并进行了推荐。  相似文献   

Proliferative glomerulonephritis leading to nephrotic syndrome in a cow     

Doré M  Morin M  Gagnon H 《The Canadian veterinary journal. La revue veterinaire canadienne》1987,28(1-2):40-41

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Transmutation and functional representation of heterogeneous landscapes   总被引：3，自引：0，他引：3  

Anthony W. King  Alan R. Johnson  Robert V. O'Neill 《Landscape Ecology》1991,5(4):239-253

Models of local small-scale ecological processes can be used to describe related processes at larger spatial scales if the influences of increased scale and heterogeneity are carefully considered. In this paper we consider the changes in the functional representation of an ecological process that can occur as one moves from a local small-scale model to a model of the aggregate expression of that process for a larger spatial extent. We call these changes spatial transmutation. We specifically examine landscape heterogeneity as a cause of transmutation. Spatial transmutation as a consequence of landscape heterogeneity is a source of error in the prediction of aggregate landscape behavior from smaller scale models. However, we also demonstrate a procedure for taking advantage of spatial transmutation to develop appropriately scaled landscape functions. First a mathematical function describing the process of interest as a local function of local variables is defined. The spatial heterogeneity of the local variables is described by their statistical distribution in the landscape. The aggregate landscape expression of the local process is then predicted by calculating the expected value of the local function, explicitly integrating landscape heterogeneity. Monte Carlo simulation is used to repeat the local-to-landscape extrapolation for a variety of landscape patterns. Finally, the extrapolated landscape results are regressed on landscape variables to define response functions that explain a useful fraction of the total variation in landscape behavior. The response functions are hypotheses about the functional representation of the local process at the larger spatial scale.  相似文献   

Torsion of abdominal organs in sows: a report of 36 cases   总被引：3，自引：3，他引：0       下载免费PDF全文

Morin M  Sauvageau R  Phaneuf JB  Teuscher E  Beauregard M  Lagacé A 《The Canadian veterinary journal. La revue veterinaire canadienne》1984,25(12):440-442

Necropsy records of 36 sows with torsion of abdominal organs involving individually the stomach, the spleen, a liver lobe or the intestine were reviewed for the years 1970 to 1983, and the age, the clinical signs and the gross lesions were recorded. These acute abdominal accidents were characterized clinically by sudden death. Dry sows from large breeding units were affected. Twenty-six cases were diagnosed between January 1981 and December 1983 while only ten cases had been seen between 1970 and 1980. Gastric torsion was the most common condition (40% of the cases) and the other three conditions were equally represented (20% each). Management practises that could be responsible for the apparent increase in occurrence of this problem are discussed.  相似文献   

Transitional Cell Carcinoma of the Urinary Bladder in a Beluga Whale (Delphinapterus leucas)   总被引：1，自引：0，他引：1       下载免费PDF全文

Martineau D  Lagacé A  Massé R  Morin M  Béland P 《The Canadian veterinary journal. La revue veterinaire canadienne》1985,26(10):297-302

A transitional cell carcinoma of the urinary bladder was found in a beluga whale stranded in the St. Lawrence middle estuary. Various organs of this animal were submitted to high resolution gas chromatography coupled with mass spectrometry analysis. High frequency of urinary bladder cancer in the human population of the same area and the presence of carcinogenic compounds in the marine environment of this animal are discussed.

Concurrent isolation of Edwardsiella tarda from various organs of this whale is also reported.

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