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1.
Bioterrorist attacks occupy a special place amongst the innumerable potential types of terrorist attack, with the intentional release of pox viruses being especially feared in this connection. Apart from the variola virus, the agent responsible for smallpox in humans, the monkeypox virus and numerous other animal pox viruses pose potential risks for humans and animals. This risk scenario also includes recombinations between the various pox viruses, changes in hosts and genetically engineered manipulations of pox viruses. For over 200 years, the method of choice for combatting smallpox was via vaccination with a reproductive, original vaccinia virus. Worldwide eradication of smallpox at the end of the 1970s and the discontinuation of routine smallpox vaccination in 1980 can be credited to such vaccination. Unfortunately, these vaccinations were associated with a large number of postvaccinal impairments, sometimes resulting in death (e.g. postvaccinal encephalitis). The only way to restrict such postvaccinal complications was to carry out initial vaccination within the first 2 postnatal years. Initial vaccination at a later age led to such a sharp increase in the number of vaccines with complications that vaccination had to be discouraged. The dilemma of the smallpox vaccine stocks stems from the fact that a large portion of these stocks are produced with the same vaccinia strains as before. This is irresponsible, especially as the percentage of immune-suppressed persons in the population, for whom vaccination-related complications pose an especial threat, is increasing. One solution to the dilemma of the smallpox vaccine stocks is the MVA strain. It is harmless, protects humans and animals equally well against smallpox and can be applied parenterally. 相似文献
2.
In recent years the fate of human and animal pathogen microorganisms as a potential pollutant of the environment has been paid increased attention. Substantial quantities of these compounds and their metabolites are excreted, flushed down the drain, discarded as waste, or left over in animal feedlots. After passing to the sewer, several of these compounds are not adequately eliminated by the methods that are currently used in sewage treatment. Substantial quantities of biosolids and livestock manure end up on agricultural land. Effective sanitation of the environment, particularly of some of its special parts, which can be a source of spreading of diseases, plays an important role in prevention of infectious diseases. In this respect special attention should be paid to the disinfection of infected farm animal excrements. Sanitation of excrements should, on the one hand, ensure effective inhibition of infectious agents and, on the other hand, comply with the requirement of preserving the composition of the manure so it can be used in agricultural production. 相似文献
3.
Hydrogen peroxide is used more and more as the water and wastewater as well as slurry disinfectant. Its advantages over other oxidants are nontoxic, harmless, and environmentally acceptable by products. The basic task in the disinfection of slurry is to destroy or remove infectious microorganisms so that the slurry cannot transmit disease producing agents, when disposed on the land or into waters. In the present study the effect of hydrogen peroxide disinfectant with catalytic action of metal ions, silver and ferrous, was investigated in the hygienization process of pig and cattle slurry. In order to determine the optimal concentration of disinfectant, the effect of a range of final concentrations of hydrogen peroxide alone and with metal ions was investigated. Organoleptic, physicochemical and bacteriologic parameters were analyzed for wastewater quality assessment in accordance with standard methods. The results illustrated an improvement of organoleptic properties: color and odor, the oxidation of organic matter across reduction of BOD5 and ammonium content of the treated slurries as well as a decrease of aerobic mesophilic bacteria and total coliform bacteria numbers. This investigation indicated that the disinfection of slurry with the oxidative compounds with hydrogen peroxide basis and catalytic action of silver and ferrous ions can be recommended for its bactericidal and oxidative effect. 相似文献
4.
A review is given of real and potential risks connected with the use of conventional and genetically engineered live and dead vaccines. Special attention is given to live carrier vaccines expressing one or more heterologous genes of other microorganisms. Because most carrier vaccines are still in an experimental phase, there is only limited experience with the risks of carrier vaccines. There are three potential risks of live carrier vaccines which will be discussed: 1. Changes in cell, tissue, of host tropism, and virulence of the carrier through the incorporation of foreign genes. 2. Exchange of genetic information with other vaccine or wild-type strains of the carrier organism. 3. Spread in the environment. Only limited experimental data are available on changes in biological behaviour of microorganisms through the incorporation of foreign genes. For example, there are indications that vaccinia virus carrying the attachment protein G of respiratory syncytial virus (RSV) replicates better in lungs of mice than vaccinia virus carrying other genes of RSV. Poxviruses carry genes that probably determine their replication in different hosts. Exchange of such host tropism genes might alter their host spectrum. Recombination between herpesvirus vaccine or wild-type strains may lead to the appearance of virulent strains with of without heterologous genes. Before carrier vaccines are applied, these risks must be thoroughly evaluated case-by-case. Potential methods for the design of safe carrier vaccines are discussed. 相似文献
5.
Apart from his direct tasks like treating diseased animals, preservation of animal health, recognition of mal-feeding and failures, recognition of unsuitable keeping systems and acknowledgement of animal welfare the veterinary practitioner can be the environmental-hygienic consultant of the farmer in following areas in particular: management and technique of feeding; management and technique of water supply; management and technique of air quality and ventilation; management and technique of manure handling and hygiene; cleaning and disinfection; deratting and pest control. The aim of these tasks is to diminish the risks/hazards for food products (food control act), the air (emission control act), surface water (law on the water household), ground water (waste control act, law on the water household) and vegetation and soil (waste control act, nature conservation act). Some examples will be given and comments are made on how to run a practice in an environmentally friendly way. 相似文献
6.
Little is known regarding the types and frequencies of contact that exist between farms and which of these may act as pathogen transmission routes; however it is likely that farms demonstrate considerable heterogeneity in such contacts. In this cross-sectional study, we explored the direct and indirect contact types and frequencies that exist between cattle farms within a region, focusing on potential routes of pathogen transmission. The owners/managers of 56 farms located in a 10 km by 10 km study area in north-west England were administered an interview-based questionnaire between June and September 2005. Information was obtained relating to contact types and frequencies, including those involving animal movements, equipment sharing between farms and any contractors or companies visiting the farms. The data was explored using hierarchical cluster analysis and network analysis. There was considerable variation between farms arising from different contact types. Some networks exhibited great connectivity, incorporating approximately 90% of the farms interviewed in a single component, whilst other networks were more fragmented, with multiple small components (sets of connected farms not linked with other farms). A range of factors influencing contact between farms were identified. For example, contiguous farms were more likely to be linked via other contacts, such as sharing of equipment and direct farm-to-farm animal movements (p < 0.001 and p = 0.02, respectively). The frequency of contacts was also investigated; it is likely that the amount of contact a farm receives from a company or contractor and whether or not biosecurity is performed after contact would impact on disease transmission potential. We found considerable heterogeneity in contact frequency and that many company and contractor personnel undertook little biosecurity. These findings lead to greater understanding of inter-farm contact and may aid development of appropriate biosecurity practices and control procedures, and inform mathematical modelling of infectious diseases. 相似文献
7.
A study was carried out to determine the possibility of a more-closed farming system for (Dutch) dairy farms. The objective of the study was to provide effective and economically profitable management advice for improving the animal-health status of farms. Management measures will only be successfully applied if supported by farmers and their advisors (such as veterinarians). Therefore, the perception of farmers and advisors of the importance of various risk factors for the introduction of diseases to a farm was determined by using bovine herpes virus type 1 (BHV1) as an example. As part of the study, an evening-long workshop was organized and run thrice. In total, 49 farmers, veterinarians and AI technicians participated in these workshops. The computerized questionnaire technique was based on adaptive conjoint analysis (ACA). ACA has the advantage that participants can work with a large number of risk factors in a relatively short period of time. Another advantage of ACA (compared with standard questionnaires) is that the answers from each participant can be checked with regard to consistency with respect to the importance assigned to them. Data from participants with inconsistent responses can be excluded from further analyses. The results of the ACA interview were compared with the risk factors reported in the literature as being associated with BHV1 status (e.g. purchase of cattle, participation in cattle shows) and with farmers' actual management to prevent the introduction of diseases. The workshop participants were all operating in the dairy sector and they seemed well aware of the risk of direct animal contacts for the introduction of BHV1. Farmers thought visitors to be more risky than did AI technicians and (especially) veterinarians. Farmers who purchased cattle or participated in cattle shows were of the opinion that the risks of direct animal contacts were more important than did farmers who were not involved in those practices. Farmers whose farms were BHV1-positive (and participated in cattle shows more often) thought the risk of participation smaller than did farmers with BHV1-negative farms. 相似文献
8.
Diagnostic inference by use of assays such as ELISA is usually done by dichotomizing the optical density (OD)-values based on a predetermined cut-off. For paratuberculosis, a slowly developing infection in cattle and other ruminants, it is known that laboratory factors as well as animal specific covariates influence the OD-value, but while laboratory factors are adjusted for, the animal specific covariates are seldom utilized when establishing cut-offs. Furthermore, when dichotomizing an OD-value, information is lost. Considering the poor diagnostic performance of ELISAs for diagnosis of paratuberculosis, a framework for utilizing the continuous OD-values as well as known coavariates could be useful in addition to the traditional approaches, e.g. for estimating within-herd prevalences. The objective of this study was to develop a Bayesian mixture model with two components describing the continuous OD response of infected and non-infected cows, while adjusting for known covariates. Based on this model, four different within-herd prevalence indicators were considered: the mean prevalence in the herd; the age adjusted prevalence of the herd for better between-herd comparisons; the rank of the age adjusted prevalence to better compare across time; and a threshold-based prevalence to describe differences between herds. For comparison, the within-herd prevalence and associated rank using a traditional dichotomization approach based on a single cut-off for an OD corrected for laboratory variation was estimated in a Bayesian model with priors for sensitivity and specificity. The models were applied to the OD-values of a milk ELISA using samples from all lactating cows in 100 Danish dairy herds in three sampling rounds 13 months apart. The results of the comparison showed that including covariates in the mixture model reduced the uncertainty of the prevalence estimates compared to the cut-off based estimates. This allowed a more informative ranking of the herds where low ranking and high ranking herds were easier to identify. 相似文献
9.
Summary A review is given of real and potential risks connected with the use of conventional and genetically engineered live and dead vaccines. Special attention is given to live carrier vaccines expressing one or more heterologous genes of other microorganisms. Because most carrier vaccines are still in an experimental phase, there is only limited experience with the risks of carrier vaccines. There are three potential risks of live carrier vaccines which will be discussed: 1. Changes in cell, tissue, of host tropism, and virulence of the carrier through the incorporation of foreign genes. 2. Exchange of genetic information with other vaccine or wild‐type strains of the carrier organism. 3. Spread in the environment. Only limited experimental data are available on changes in biological behaviour of microorganisms through the incorporation of foreign genes. For example, there are indications that vaccinia virus carrying the attachment protein G of respiratory syncytial virus (RSV) replicates better in lungs of mice than vaccinia virus carrying other genes of RSV. Poxviruses carry genes that probably determine their replication in different hosts. Exchange of such host tropism genes might alter their host spectrum. Recombination between herpesvirus vaccine or wildtype strains may lead to the appearance of virulent strains with of without heterologous genes. Before carrier vaccines are applied, these risks must be thoroughly evaluated case‐by‐case. Potential methods for the design of safe carrier vaccines are discussed. This article is based on a contribution to the course ‘Introduction of Genetically Modified Organisms into the Environment: Biosafety Aspects’, 4–14 December 1991, Wageningen, the Netherlands. 相似文献
10.
The commercial applications in agriculture of new breeding technologies, as well as conventional breeding strategies, have the potential to influence animal welfare in both positive and negative ways. For example, the sexing of cattle semen might be used to reduce the number of unwanted male dairy calves provided that the technique had not been shown to produce adverse effects. On the other hand, inappropriate use of some breeding technologies may create new problems, or exacerbate welfare problems that may already have arisen within conventional livestock breeding. It is the impact of any breeding technology or strategy that is important to welfare, whether it is the quality of life of the offspring that is compromised, or whether it is the application of the technology itself that causes pain, distress or lasting harm to the subject animal. The aim of this paper is to provide clear and practical advice on the establishment of an appropriate framework within which developments in animal breeding and breeding technologies, and the outcome of such processes, may be considered, monitored and, where necessary, regulated. It builds on recommendations recently made by the FAWC to UK Government, and considers the wider public interest in these technologies. Finally, the response from stakeholders is considered in attempting to ensure that such controls do not render production systems non-competitive in a global livestock industry. 相似文献
11.
旨在为研究者深入研究蚯蚓处理粪污技术提供一定参考和借鉴。通过查阅与蚯蚓处理粪污技术相关的文献资料,得出影响蚯蚓处理粪污效果的主要因素有蚯蚓品种选择、环境因素、粪便腐熟程度和粪便组合及辅料成分等。其中,爱胜蚓属的太平2号蚯蚓为国内外专家研究使用最多、实际应用中最广泛的蚯蚓品种;使用蚯蚓处理粪便时,温度保持在15-25℃,pH值应该控制在中性范围内;最适宜蚯蚓生长繁殖的畜禽粪便为牛粪,处理其他动物粪便时加入牛粪形成粪便组合进行处理,牛粪所占比例一定最多。关于湿度和粪便腐熟程度对蚯蚓处理粪便效果的影响、辅料的选择,以及对于除环境因素外的其他3项因素（蚯蚓品种选择、粪便腐熟程度、粪便组合及辅料成分）在不同情况下的选择需要进一步研究。 相似文献
12.
The amendment of the German Veterinary Legislation concerning the eradication of notifiable diseases demanded also an updating of the relevant disinfection measures and technologies. Some hints are given, based on own experimental results, for the choice of chemical disinfectants, on some special problems of disinfection in livestock buildings and of disinfection of animal slurry and farm-yard manure as well as on biotechnological disinfection methods and environment-friendly disinfectants. 相似文献
13.
A number of different acaricides provide highly effective control of tick populations on dogs and cats. These acaricides are formulated as sprays, dips, dusts, or shampoos for use on the animal. Further protection of the animal from reinfestation with ticks can be achieved with the use of acaricide-impregnated flea and tick collars. Some of these acaricides are registered with the EPA for indoor and outdoor use as controls for free-living populations of ticks. Caution should be used when applying these materials. The label directions for the application of the acaricide and disposal of the acaricide containers should always be followed. Removal of underbrush and leaf litter, thinning trees, and frequently mowing grasses help reduce the number of free-living ticks. Any reduction in the amount of wildlife food sources and cover areas potentially decreases populations of ticks and thus reduces the potential of these ticks parasitizing a dog or cat. Application of an acaricide for area-wide control of free-living ticks in the spring, summer, and autumn also reduces the number of ticks. New approaches to area-wide control of ticks by use of acaricides that are focused on controlling the ticks attached to small mammal hosts are discussed. Although research has shown that reductions in tick numbers can be achieved using these methods, acceptance of these methods by regulatory agencies and the public requires further research. 相似文献
14.
The methods of biotechnology especially of recombinant technology opened new horizons for studies and directed control of the genomic deoxyribonucleic acid of plants, animals and men. These chances for plant breeding and animal husbandry include techniques for improved diagnosis and prophylaxis of infectious diseases or genetic defects. However, we have also to very carefully consider the potential risks of these techniques which cannot be fully evaluated at present. In this paper some of the ethic, moral and social consequences will be discussed. 相似文献
15.
The objective of this review is to consider the ethics of stockmanship, particularly from the perspective of the nature and extent of the duties of stockpeople to their farm animals. It will consider what science tells us about the impact of stockmanship on the animal, particularly the welfare of the farm animal. The effects of human-animal interactions on the stockperson will also be considered, since these interactions affect the work performance and job satisfaction of the stockperson and thus indirectly affect animal welfare. Animal ethics is broader than animal welfare and includes economic as well as philosophical, social, cultural and religious aspects. This paper is predicated on the view that farm animals can suffer, and that animal suffering is a key consideration in our moral obligations to animals. Housing and husbandry practices affect farm animal welfare and thus farmers and stockpeople have a responsibility to provide, at minimum, community-acceptable animal housing and husbandry standards for their animals. The farmer's or stockperson's attitudes and behaviour can directly affect the animal's welfare and thus they also have a responsibility to provide specific standards of stockmanship for these animals. However, research suggests that the behaviour of some stockpeople is not as correct as it might be. Such situations exemplify the inevitably unequal human - domestic animal relationship, and this inequality should be considered in analysing the boundary between right and wrong behaviour of humans. Thus ethical discussion, using science and other considerations and involving stockpeople, livestock industries, government and the general public, should be used to establish and assure acceptable stockperson competencies across the livestock industries. Training programs targeting the key attitudes and behaviour of stockpeople presently offer the livestock industries good opportunities to improve human-animal interactions. 相似文献
16.
Animal welfare and environmental protection are increasingly important. Housing systems must be found that offer animal welfare while minimizing the overall emissions of ammonia and greenhouse gases. The straw flow system is an animal friendly housing system for fattening pigs, which can be operated economically on commercial farms. Emissions from conventional slurry based pig houses have been intensively studied, but more research is needed into straw based systems. In this study, we quantified emissions of ammonia and greenhouse gases from a straw flow system with or without daily removal of slurry to an outside store. The effect of applying a solid cover during outside storage was also examined. Emissions of NH3, N2O, CH4, and volatile organic C (VOC) from a commercial straw flow system for fattening pigs in Upper Austria were measured between June 2003 and March 2004. Emissions of CH4 during housing were 1.24 and 0.54 kg CH4 per pig place per year without and with daily manure removal, respectively. The corresponding N2O emissions amounted to 39.9 and 24.5 g N2O per pig place per year, and NH3 emissions to 2.10 and 1.90 kg NH3 per pig place per year without and with daily manure removal. Emissions of CH4, N2O and NH3, and of total greenhouse gases, from the straw flow system were lower than literature reference values for forced ventilated fully slatted floor systems. Daily removal of the manure to an outside store reduced emissions from the pig house. Emissions during storage of pig slurry derived from a straw flow system were quantified between June 2004 and June 2005. Slurry was stored in pilot scale stores with or without a solid cover and emissions quantified by a large open dynamic chamber. The solid cover reduced NH3 and greenhouse gas emissions by 30 and 50%, respectively. During cold climatic conditions stored pig manure emitted less NH3 and greenhouse gases than when stored under warm climatic conditions. We recommend the use of separate emission factors for slurry storage in the colder and warmer periods in the national emission inventory, and the use of covers on pig slurry stores. Overall, it is concluded that the straw flow system may combine recommendations of animal welfare and environmental protection. 相似文献
17.
The study of animal welfare cannot be based entirely on science. For a number of assumptions of an ethical nature will it inevitably enter the study of how good or bad animals fare under different systems of animal production. In some cases, ethical assumptions may be uncontroversial, but they may also be the cause of disagreement. A case study is presented that seems to indicate that there is systematic disagreement between lay and expert views about what a good animal life is. The study is based on interviews about modern pig production. The title of this paper summarises the reaction of an interviewee when commenting on pictures of what is generally regarded as animal-friendly pig production. In the lay perspective, living a natural life is an important part of animal welfare – a part that supplements, and therefore needs to be combined with, the absence of suffering and frustration that are central components of the expert approach. The main message of the paper for those who are professionally involved in animal production is that ethical assumptions and potential conflicts of view should be recognised and brought into the discussion of animal welfare. 相似文献
18.
厌氧消化技术是一种有效处理动物粪便的方式,论文综述了微生物发酵产沼气的机理和动物粪便的热处理、化学处理、热化学处理、机械处理和超声波处理等预处理方法,探讨了单相和两相厌氧消化、单级和多级厌氧消化工艺,并分析了影响沼气产量的各种因素。 相似文献
19.
宿主防御肽是动物体产生的一种多功能肽,不仅具有广谱的抗菌功能,还可作为先天性免疫调节因子,有效增强动物机体免疫力,阻止病原微生物的侵扰,对保证动物健康具有重要意义。宿主防御肽在动物体内的表达受到日粮中各种营养物质的调控,有研究者认为,以营养调控的方式促进宿主内源防御肽的表达有益于动物健康和生产性能的提高,是未来实现无抗、健康养殖的可能策略之一。本文综合论述了动物饲粮中多种营养物质对宿主内源防御肽表达的调控作用,为评价营养物质调节宿主免疫和对动物健康及生产的影响提供新的理论参考。 相似文献
20.
有毒有害物质如致病微生物、生物毒素、农药、兽药及添加剂残留等会造成极大的食品安全隐患,严重威胁人类健康。目前,对有毒有害物质的风险监测仍然面临着巨大挑战。代谢组学技术通过考察生物受到有毒有害物的刺激或干扰后代谢产物的变化,进行系统的定量定性分析,获得具有高度敏感性及特异性的代谢组学投影,适用于对多种微量毒物的鉴别监测。同时,代谢组学技术可反映出毒物代谢过程中可能的生物标志物,为毒物代谢过程和毒理机制的进一步研究提供参考。因此,以色谱质谱联用、核磁共振等为代表的代谢组学方法逐渐成为检测和研究有毒有害物质的关键技术,为其风险评估提供依据。同时各种生物标志物的发现及检测方法的优化将进一步促进代谢组学技术在毒物监测中的实际应用。作者介绍了代谢组学技术的产生和发展,总结了代谢组学技术对常见有毒有害物质的检测方法和生物标志物的研究进展,旨在为代谢组学技术在有毒有害物质检测中的进一步应用提供参考。 相似文献
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