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1.
Between 1980 and 1987 1153 ovine fetuses and placentas were examined after abortion. In 68.5% of the cases a cause of abortion could be diagnosed as follows: 43.5% Chlamydia psittaci var. ovis, 10.7% Salmonella abortus ovis, 3.7% Coxiella burnetii, 3.3% Listeria monocytogenes and 0.4% Campylobacter fetus intestinalis. Hemolyzing Escherichia coli and Streptococci, Yersinia pseudotuberculosis, Salmonella typhimurium, Salmonella enteritidis, Corynebacterium pyogenes and other facultative pathogens isolated in pure culture out of fetal organs as well as non-infectious reasons (fetal deformities) were the causes of abortion in only 7%.  相似文献   

2.
通过对产奶量较高的萨能奶山羊和优秀的地方品种成都麻羊的调查和分析,结果表明,萨能奶山羊不仅具有较高的产奶量,良好的乳房、乳头外特征,且日挤奶量高、与奶牛挤奶有近似的频率和真空度,适合于机械挤奶;成都麻羊尽管有较好的繁殖性能,但泌乳性能较差,不适合机械挤奶。  相似文献   

3.
The utility of four commonly used models for estimating population size in teleosts was tested. Sixty-five individually marked largemouth bass, Micropterus salmoides, were introduced into a concrete pond. Fishing surveys were conducted every 2 days for a period of 19 days. The collected data were then used to estimate the population size under a variety of conditions using the following models: mark/recapture (Petersen method), DeLury (first model), and two models of the software program Capture. Comparison of the actual population size with population estimates obtained using the mark/recapture method showed that the percentage of absolute error was <30% in all cases in which the number of fish caught and marked in the first survey was >30% of the population. Using the DeLury method and Model 1 of Capture, the population estimates were biased toward underestimation, but the error was <30% when the number of fish caught in all surveys was >70%. In contrast, in Model 2 of Capture, the error was relatively small when the percentage of fish caught in all surveys was <70%. These conditions for minimizing errors should be taken into account by fisheries managers when estimating the population size of largemouth bass.  相似文献   

4.
Book reviews     
Book reviewed in this articles:
Textbook of Fish Diseases for Veterinarians and Biologists , 3rd edn. By E rwin A mlacher .
Marine Ecology and Fisheries . By D.H. C ushing
Eel Capture, Culture, Processing and Marketing . By D avid M. F orrest .
Eel Capture, Culture, Processing and Marketing . By D avid M. F orrest .  相似文献   

5.
6.
The article is based on the analysis of selenium concentration in blood plasma of 9 goats and their kids (n = 17), from two different places, as well as of 12 sheep and their lambs (n = 19) from several flocks. The selenium concentration was measured using ASS. In addition, the activity of CK was determined enzymatically. There was a low plasma selenium level in lambs and goat kids immediately post-natal depending on the selenium state of the mothers. After application of vitamin E and selenium to a group of lambs their selenium levels increased remarkably over 24 hours. Ten days later the average selenium concentration in the plasma of those animals that had been treated was three times as high as that of the control group. It was shown that the absorption of vitamin E and selenium when given orally to newborn lambs is comparable with the absorption after parenteral application, and that a significant increase of the plasma selenium level is attainable by oral application.  相似文献   

7.
A virological analysis was conducted on wild eels from the Albufera Lake (Spain). A total of 179 individuals at different growth stages were collected in two different surveys (2004 and 2008). Presence of anguillid herpesvirus (AngHV‐1), aquabirnavirus and betanodavirus was confirmed by PCR procedures in both surveys, although the number of detections was clearly higher in 2008 (83% of the eels analysed resulted positive for virus presence). AngHV‐1 was the viral agent most frequently detected, followed by aquabirnaviruses. Betanodaviruses were detected by the first time in wild eels, and although the detections were only made by nested PCR, high percentage of positives were achieved. In addition, in 2008, seven aquabirnaviruses were isolated. Phylogenetic analysis performed using partial sequences of both genomic segments of aquabirnaviruses indicated that the seven isolates could be typed as WB (genogroup I) on the basis of segment A sequences, but when segment B was used six of them clustered with C1 strain (genogroup V) and one was typed as Ab (genogroup II). These results indicate natural reassortment between different strains of aquabirnaviruses in the eels. Although betanodaviruses were not isolated in cell culture, the analysis of the sequence of the nested PCR product indicated that they clustered with SJNNV genotype. The diversity of viral agents and the high level of viral detections suggest that viral infections may play a more prominent role in the decline of the European eel than initially thought.  相似文献   

8.
50 goats of several breeds and crossbreeds as well as their kids were observed. The experiment involved 388 hours of observation over 62 days. The average duration of pregnancy was 151.2 days. In addition to physical characteristics and labored mobility, a tendency toward isolation and characteristic vocalization were noted. The period from onset of birth to the first delivery averaged less than 20 min. Subsequent to delivery the doe arose immediately, followed by the kid in an average of 21 min. Initial suckling by the kids occurred on average 42 min after birth. After an initially high frequency of suckling cycles, the cycle in the following weeks was reduced to 1 to 2 times an hour in the case of a single kid birth, while twins suckled more often. Out of 5,562 observations, only 1% were true cases of suckling from another doe.  相似文献   

9.
抗软骨藻酸单克隆抗体杂交瘤细胞株的构建   总被引:3,自引:0,他引:3  
为了获得稳定、高效分泌抗软骨藻酸(DA)单克隆抗体的杂交瘤细胞株,采用活泼酯法制备软骨藻酸免疫抗原(DA-KLH)和包被抗原(DA-BSA),以DA-KLH免疫BALB/c小鼠,用细胞融合技术筛选抗软骨藻酸单克隆抗体杂交瘤细胞株,体内诱生腹水法制备大量单抗,捕获EL ISA法测定小鼠免疫球蛋白亚型,间接ELISA法测定腹水效价;用G蛋白亲和层析法来纯化腹水。结果显示,成功构建2株能稳定分泌DA单克隆抗体(McAb)的杂交瘤细胞株2B1和4C2,抗体亚类分别为IgG1和IgG2a,间接EL ISA检测小鼠腹水的抗体效价达1∶64 000,腹水纯化后蛋白浓度为1.27和0.675 mg/mL。研究结果表明,成功制备的抗DA单克隆抗体杂交瘤细胞株稳定、高效,为利用该单抗研制快速检测软骨藻酸的胶体金免疫层析试纸条打下基础。  相似文献   

10.
The udder health of 404 sheep from 23 flocks and 397 goats from 15 herds in Lower Austria was examined. In order to determine cell levels, the Schalm Test (equivalent to the California mastitis test) and a fluoroscopic "Fossomatic" cell count appliance were employed. The resultant physiological median levels of somatic cell content were established as 71,000 cells/ml for sheep milk and 415,000 cells/ml for goat milk. Significant factors influencing the cell count levels were the milking technique in both species and age in sheep but not in goats. The pathogens most frequently isolated as causes of chronic or latent mastitis were coagulase-positive and -negative cocci.  相似文献   

11.
The minimum inhibitory concentrations (MICs) of 15 chemotherapeutic agents were tested against 146 Lactococcus garvieae strains isolated from 1999 to 2006 in Japan. The agents used included chloramphenicol, ciprofloxacin, erythromycin (EM), enoxacin, fleroxacin, florfenicol, kanamycin, lincomycin (LCM), norfloxacin, oxolinic acid, orbifloxacin, ofloxacin, benzylpenicillin, streptomycin and tetracycline (TC). Of the tested strains, 46 showed high levels of resistance to EM, LCM and TC. Twelve of these strains were detected to be carrying transferable R-plasmids using a conjugation experiment and, using Southern hybridization, were shown to have the same structure as the R-plasmid. The remaining 34 resistant strains had a similar DNA structure to that of the R-plasmid as confirmed by polymerase chain reaction (PCR) using primers designed from sites in the transferable R-plasmid. The EM and TC resistance genes were classified into the ermB and tetS groups using PCR. We also detected gyrA and/or parC mutants that are highly resistant to old and new generation quinolones. This study revealed that transferable R-plasmids encoding EM, LCM and TC are widely distributed and are conserved regardless of the area and/or time of collection.  相似文献   

12.
In response to concerns that novel infectious agents were introduced through the movement of eggs as Atlantic salmon aquaculture developed in British Columbia (BC), Canada, we estimated the prevalence of infectious agents in archived return‐migrating Sockeye salmon, from before and during aquaculture expansion in BC (1985–94). Of 45 infectious agents assessed through molecular assays in 652 samples, 23 (7 bacterial, 2 viral and 14 parasitic) were detected in liver tissue from six regions in BC. Prevalence ranged from 0.005 to 0.83 and varied significantly by region and year. Agent diversity ranged from 0 to 12 per fish (median 4), with the lowest diversity observed in fish from the Trans‐Boundary and Central Coast regions. Agents known to be endemic in Sockeye salmon in BC, including Flavobacterium psychrophilum, Infectious haematopoietic necrosis virus, Ceratonova shasta and Parvicapsula minibicornis, were commonly observed. Others, such as Kudoa thyrsites and Piscirikettsia salmonis, were also detected. Surprisingly, infectious agents described only recently in BC salmon, Ca. Branchiomonas cysticola, Parvicapsula pseudobranchicola and Paranucleospora theridion, were also detected, indicating their potential presence prior to the expansion of the aquaculture industry. In general, our data suggest that agent distributions may not have substantially changed because of the salmon aquaculture industry.  相似文献   

13.
A multigear sampling method to quantify fish richness and abundance in Amazonian Terra firme streams was assessed. This method is based on the four‐pass removal method using the combined application of different nets. The efficiency of the method was explored over 10 replicated sites along three streams over day, night and seasons. Use of four successive passes allowed both abundant and rare species to be collected and the abundance of common species to be estimated. On average, a high proportion (41%) of rare species was collected per sample (only one or two individuals) after four fishing passes. The efficiency of the sampling method to detect species richness per sample between successive passes was estimated using an autosimilarity approach. Although species richness and abundance increased with successive passes, no major differences were obtained between the third and fourth pass. A single pass considerably underestimated the richness and abundance of species in these type of streams, and night sampling also increased beta‐diversity by at least 20%. Abundance estimates demonstrated high efficiency with an overall sampling error of only 8 and 11% for samples and single species, respectively. Capture efficiency differed among fish species exhibiting different ecological traits and showed significant differences among seasons for total samples. Results supported the robustness of the method and its suitability to quantify fish richness and abundance in small, wadeable Amazonian Terra firme streams inhabited by highly diverse fish assemblages.  相似文献   

14.
The presence of anti-microbial-resistant bacteria in the aquatic environment remains a matter of concern for environmental, animal and human health risks. Many published data have reported increased anti-microbial resistance among the aquatic microbiota from fish farm environments which often coincides with the use of anti-microbial agents. It can be assumed that the selection of anti-microbial-resistant bacteria first occurs in the fish farms themselves, at locations where anti-microbial concentrations are active. As anti-microbial agents are frequently administered through feed pellets, faecal matter excreted could favour conditions for such selection. In this study, OA (oxolinic acid) concentrations and OA resistance of Aeromonads were surveyed in output water and in faecal matter from OA medicated (test) and non-medicated (control) fish tanks during and after an OA oral treatment. Because of the low counts of Aeromonads in the output water, it was not possible to obtain reliable data on the proportion of anti-microbial resistance in this compartment. On the other hand, a time-limited effect on the abundance of Aeromonads isolated from faecal matter was only observed in test tanks. In these tanks, high proportion (80-100%) of OA-resistant Aeromonads was present in deposited faecal matter until at least one week after the end of the anti-microbial treatment. At that time OA was no longer detected within the faecal matter, after having reached concentrations between 100 and 190 μg/g during the treatment. We discuss how the leaching of OA from faecal pellets, from the intestine to their deposit, may favour the selection of OA-resistant Aeromonads. Further investigations in real conditions on microbiota associated with faecal matter in transit through the fish farm system are required. Particular attention should be paid to the wastes collected by the filter treatments of fish farm effluents.  相似文献   

15.
Contagious pustular dermatitis (CPD, contagious ecthyma, Orf) is a highly contagious viral disease afflicting sheep and goats. The infectious agent is a parapoxvirus which is widespread and also contagious for humans (zoonosis). Recently the disease in sheep and goats is marked by increased incidence and severe cases which cause many losses especially among lambs in fattening farms. The immunity of once infected animals is based on cellular defense mechanisms which are very unstable. The most suitable method for the prevention of ecthyma is parenteral vaccination with attenuated live vaccines. Effective vaccination programmes should enclose the whole animal population at intervals of 6-8 months.  相似文献   

16.
选用南江黄羊断奶羊羔10只,按性别、年龄、体重基本一致的原则随机分为对照组和试验组,每组4只公羊,1只母羊,进行45d舍饲饲养试验。试验组在与对照组基础日粮相同的日粮中添加0.15mg/kg的硒。结果表明:试验期对照组和试验组只均增重分别为(4.25±0.68)kg、(5.6±0.78)kg,平均日增重分别为93.34g和124.46g,两组间增重差异显著(P<0.05)。  相似文献   

17.
由于具有较高的生物活性,卟啉铁在动物机体内的吸收率比一般补铁剂高很多,作为一种优质高效铁源,卟啉铁已逐步被发展成为一种新型绿色饲料添加剂。在养猪生产中,卟啉铁可作为高效铁源补充猪对铁的需求,并能有效改善猪的生长性能和外观。随着有毒副作用的促生长剂慢慢退出猪饲料添加剂行列,卟啉铁在畜牧养殖中必将发挥出重要的作用。  相似文献   

18.
罗非鱼、南美白对虾体内药残状况研究   总被引:1,自引:0,他引:1  
以广东省养殖罗非鱼及南美白对虾为实验对象,就其体内土霉素等多种渔药残留及分布状况进行研究, 比较不同规格罗非鱼及南美白对虾体内渔药残留差异,分析渔药在罗非鱼及南美白对虾不同部位的残留状况。结果表明在罗非鱼体内已烯雌酚、呋喃唑酮、氯霉素3种渔药未见检出,南美白对虾体内已烯雌酚、呋喃唑酮、氯霉素、(口恶)喹酸和喹乙醇5种渔药均未见检出,而土霉素等常规用药在罗非鱼和南美白对虾体内均有不同程度的检出。渔药残留量因其规格大小及部位而异,趋势为大规格样品渔药残留量相对较高,在罗非鱼及南美白对虾体内的增长情况与其体重具有负相关性;罗非鱼内脏渔药残留量明显高于肌肉组织,虾头为虾渔药残留的主要场所。  相似文献   

19.
Bluetongue virus (BTV), an arthropod-borne virus, is transmitted primarily by biting midges of the genus Culicoides. Some insect species, which might serve as a potential vector, are prevalent in Central Europe. In sheep, bluetongue is acute and mortality is high, whereas in cattle, goats and most wild ruminants the infection is usually clinically inapparent. Viremia is of short duration in sheep, but cattle experience a prolonged viremia and provide a reservoir for the dissemination of BTV. At least 24 different BTV serotypes have been identified. Antigenic variations occur in the polypeptides of the outer viral capsid and the segmented nature of the viral genome provides the potential for evolution of the virus by a mechanism of reassortment. This renders the use of polyvalent vaccines inefficient and emphasizes the significance of import/export restrictions on ruminants from BTV endemic areas.  相似文献   

20.
Book Reviews     
Book reviewed in this article:
Biological Diversity: The Coexistence of Species on Changing Landscapes . By Michael A Huston.
Restoration Planning for the Rivers of the Mississippi River Ecosystem . Edited by L.W. Hesse.
Shrimp Capture and Culture Fisheries of the United States . By E.S. Iverson, D.M. Allen & J.B. Higham.  相似文献   

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