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在战后年代里,英国乳业的模式和生产率均已发生了巨大变化。复合饲料的改进、遗传学的进展以及畜牧管理技术的提高,所有这些都使英国的乳业技术变得更加高效。但是,乳业现在正在经历结构上重大而快速的变化,从而不可避免地使乳业的规模变小而生产经营更加集约化,乳业与其最终消费者之间的关联将达到前所未有的密切程度。 相似文献
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文章回顾了我国楼房猪场的发展历程,区分了传统平层猪场堆叠起来的楼房猪场和基于楼房特点优化设计的新式楼房猪场,重点描述了当前楼房猪场的特点及问题.可以看出,新式楼房猪场是养猪先进生产力的代表,具有强大的生命力和发展前景. 相似文献
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Brucellosis vaccines: past,present and future 总被引:20,自引:0,他引:20
The first effective Brucella vaccine was based on live Brucella abortus strain 19, a laboratory-derived strain attenuated by an unknown process during subculture. This induces reasonable protection against B. abortus, but at the expense of persistent serological responses. A similar problem occurs with the B. melitensis Rev.1 strain that is still the most effective vaccine against caprine and ovine brucellosis. Vaccines based on killed cells of virulent strains administered with adjuvant induced significant protection but also unacceptable levels of antibodies interfering with diagnostic tests. Attempts were made to circumvent this problem by using a live rough strain B. abortus 45/20, but this reverted to virulence in vivo. Use of killed cells of this strain in adjuvant met with moderate success but batch to batch variation in reactogenicity and agglutinogenicity limited application. This problem has been overcome by the development of the rifampicin-resistant mutant B. abortus RB51 strain. This strain has proved safe and effective in the field against bovine brucellosis and exhibits negligible interference with diagnostic serology. Attempts are being made to develop defined rough mutant vaccine strains that would be more effective against B. melitensis and B. suis. Various studies have examined cell-free native and recombinant proteins as candidate protective antigens, with or without adjuvants. Limited success has been obtained with these or with DNA vaccines encoding known protective antigens in experimental models and further work is indicated. 相似文献
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Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals including cattle, pigs, sheep and many wildlife species. It can cause enormous economic losses when incursions occur into countries which are normally disease free. In addition, it has long-term effects within countries where the disease is endemic due to reduced animal productivity and the restrictions on international trade in animal products. The disease is caused by infection with foot-and-mouth disease virus (FMDV), a picornavirus. Seven different serotypes (and numerous variants) of FMDV have been identified. Some serotypes have a restricted geographical distribution, e.g. Asia-1, whereas others, notably serotype O, occur in many different regions. There is no cross-protection between serotypes and sometimes protection conferred by vaccines even of the same serotype can be limited. Thus it is important to characterize the viruses that are circulating if vaccination is being used for disease control. This review describes current methods for the detection and characterization of FMDVs. Sequence information is increasingly being used for identifying the source of outbreaks. In addition such information can be used to understand antigenic change within virus strains. The challenges and opportunities for improving the control of the disease within endemic settings, with a focus on Eurasia, are discussed, including the role of the FAO/EuFMD/OIE Progressive Control Pathway. Better control of the disease in endemic areas reduces the risk of incursions into disease-free regions. 相似文献
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The increasing international movement of horses combined with the relaxation of veterinary regulations has resulted in an increased incidence of equine infectious diseases. Vaccination, along with management measures, has become the primary method for the effective control of these diseases. Traditionally modified live and inactivated vaccines have been used and these vaccines have proven to be very successful in preventing disease. However, there are a number of equine infectious diseases for which conventional technology has shown its limitations. The advent of recombinant technology has stimulated the development of second generation vaccines, including gene deleted mutants, live vectored vaccines and DNA vaccines. These vaccines have in common that protective antigens are endogenously processed and presented along the molecules of the MHC I and MHC II complex, resulting in the stimulation of both humoral and cell-mediated immune responses similar to natural infection. The present paper provides a review of the vaccines being employed today against the most important equine viral diseases followed by a summary of new developments that are expected to bring improved vaccines to the market in the foreseeable future. 相似文献
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Adult mesenchymal stromal cells are plastic-adherent cells that are self-renewing and have the capacity to differentiate into various tissue specific lineages. Stromal cells were initially discovered over 100 years ago and substantial insight into stromal cell identification, isolation, characterization, and differentiation has been made, including efforts to elucidate the factors involved in stromal cell differentiation. Stromal cells have immune privilege and thus are attractive candidates for tissue engineering and regenerative medicine applications. Positive results from a number of recent investigations support the use of adult mesenchymal stromal cells for clinical application. This review article provides a brief overview of past, present, and future stromal cell technology. 相似文献
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Wardrop KJ 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2005,34(4):325-334
The Coombs' test, also known as the antiglobulin test, is used most frequently in veterinary medicine as an aid in the diagnosis of immune-mediated hemolytic anemia. The test also is used widely in human medicine to screen for red blood cell alloantibodies. Polyspecific reagents for veterinary use typically contain anti-IgG, anti-IgM, and anti-C3. Monospecific reagents also are available. False-positive and false-negative test results can be obtained. Inadequate sensitivity of the standard test in human and veterinary medicine has necessitated development of alternate, more sensitive technologies. 相似文献
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R K Dickens 《Australian veterinary journal》1975,51(10):459-463
The koala (Phascolarctos cinereus) (from the Greek phascolarctos meaning leather pouch and bear, cinereus ashen grey in colour) is Australia's most admired native animal but very little scientific reference material is available on this unique animal. The demands of the fur trade during the latter half of the last century and up to the 1920's almost exterminated the koala and this tragic episode from the past is briefly recounted. Koalas are nocturnal and arboreal. Details of appearance, distribution, breeding, diet, water intake, volatile eucalypt oil detoxication and handling are briefly described, while information concerning intravenous injections, anaesthetic agents antibiotic therapy and fluid therapy are given. As an aid to veterinarians presented with koalas to examine, tables are presented for physiological, haematological and biochemical values. Pathological conditions found on post mortem examination are summarised, while disease conditions such as anaemia, keratoconjuctivitis, toxoplasmosis, cryptococcocis, reproductive disorders, miscellaneous conditions and internal and external parasites are mentioned. Finally, the future of the koala is discussed. Diminishing habitat, depletion of food supplies, bushfires, the threat of disease, coupled with a paucity of relevant scientific information, create an uncertain future for the koala. A plea is made to totally protect and expand the very few remaining known koala breeding areas especially in Victoria, and for veterinarians to become involved in conservation programs and wildlife research in order that the future of the koala in common with all other native species may be assured. 相似文献
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S. F. J. Hodgman 《The Journal of small animal practice》1964,5(3):263-270
The twenty-first anniversary of the A.H.T. also completes fifteen years of work at the Canine Health Centre of the Trust. During this period a considerable amount of valuable investigational and research work has been conducted and completed. We have asked the Director, Mr. S. F. J. Hodgman, to record his thoughts and opinions on the future development of his programme of work in the small animal field. 相似文献