The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform
Zhang Qian - One of the best experts on this subject based on the ideXlab platform.
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Biological Characterization of Newcastle Disease Virus of Goose Origin
Chinese journal of veterinary science, 2006Co-Authors: Zhang QianAbstract:The goose′s Newcastle Disease has been do great harm to goose flocks as a main virus Disease.Many domestic scholars think that there is an analogy between the goose′s Newcastle Disease and chicken′s Newcastle Disease.In the present test, the biology characteristic and the analyse of molecule epidemiology were explored including virus shape,pathogenicity,partial sequence analysis of the fusion(F) genes,animal test and the dissection alterations of the death gooses.The results demonstrated that the two isolates goose′s Newcastle Disease virus and chicken′s Newcastle Disease virus belong to one kind of virus,and not two kinds of virus.Just the virulence of the goose′s Newcastle Disease virus is stronger than chicken′s Newcastle Disease virus and it can result in gooses Disease.
P. B. Spradbrow - One of the best experts on this subject based on the ideXlab platform.
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Thermostable Newcastle Disease vaccines.
2001Co-Authors: P. B. SpradbrowAbstract:Robust vaccines are required to protect village chickens against Newcastle Disease. Thermostable vaccines derived from avirulent Australian strains of Newcastle Disease virus (strains V4 and I-2) have proved successful for this purpose. These vaccines have been developed through ACIAR projects and have been adopted by other international aid agencies. It is now possible to offer integrated workshops in which administrators and field workers are trained in the use of thermostable vaccines, poultry-specific extension activities and gender aspects of poultry production. At the same time, laboratory workers are taught the skills required to produce and test thermostable vaccine on a small scale, and to assure the quality of the product. Vaccine seed material is supplied without cost. Recent events in Australia have led to some concern among potential users of the vaccine. Virulent strains of Newcastle Disease virus have apparently risen from the avirulent strains that have been circulating in Australia for at least 30 years. Some have suggested that the virulent strains of Newcastle Disease virus first recognised in 1926 were derived by a series of mutations from pre-existing avirulent viruses. The virulence of strains of Newcastle Disease virus is currently judged by the sequence of amino acids at the cleavage site of the viral fusion (F) protein. Work in several laboratories has indicated that the sequences in V4 and I-2 are similar to those in other mild vaccine strains. One mesogenic vaccine strain used in developing countries has the same sequences as velogenic viruses. It is also argued that the Australian ‘virulent’ viruses do not produce a Disease with high mortality and would be insignificant pathogens compared with Newcastle Disease viruses that circulate in Africa and Asia. Thermostable Newcastle Disease vaccines, locally produced and widely distributed, would allow village chickens to contribute fully to alleviating poverty and improving nutrition in rural areas. Suitable systems of extension and cost recovery would make the enterprise sustainable. MOST people attending this meeting would agree that village chickens are a very important resource for populations in rural and peri-urban areas in developing countries. Most would agree that village flocks are not managed to produce at their full potential. In most cases, the major constraint to enhanced productivity is the viral Disease known as Newcastle Disease, which devastates poultry populations in developing countries. Commercial vaccines and attention to biosecurity are important steps in the control of Newcastle Disease in commercial chickens. Only over the past 10 or 15 years have we been able to contemplate the control of Newcastle Disease in village chickens. The key has been the production of vaccines that are cheaper, less complex and more robust than commercial Newcastle Disease vaccines. The problems have been many. The flocks are small, scattered and multi-aged. The owners of the chickens (often women) lack economic or political influence, and veterinary and extension services are seldom responsive to their needs. Commercial vaccines are not suitable for use in resource-poor villages. Individual vials contain at least 1000 doses (economies of scale), the vaccines are heat-labile and require continuous refrigerated storage and if imported they are a drain on foreign exchange. The author believes that these problems can be overcome, and bases this assertion on his experience with control of Newcastle Disease since 1984. In many places, it is not yet feasible to construct cold chains to link vaccine producers to village flocks, so thermostable vaccines are required. Not all the chickens can be caught readily for vaccination, so 1 Emeritus Professor Peter Spradbrow, AM, Division of Veterinary Pathology and Anatomy, University of Queensland, PO Box 125, Kenmore, Brisbane 4069 Australia.
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Recent isolates of Newcastle Disease virus in Australia
Veterinary Microbiology, 1995Co-Authors: P. B. Spradbrow, M. Mackenzie, S. E. GrimesAbstract:Forty-five recently isolated strains of Newcastle Disease virus and the V4 vaccine strain of Newcastle Disease virus were used to infect experimental chickens. Neither V4 nor any of the new strains produced detectable clinical Disease. All the viruses produced an antibody response and spread by contact. Some of the newly isolated viruses produced a more rapid serological response than V4 virus did. Dual or multiple infections with one of the new strains of Newcastle Disease virus, infectious bronchitis virus and Escherichia coli did not enhance the pathogenicity of any of the agents. © 1995.
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Evaluation of an oral Newcastle Disease vaccine in Thailand
Preventive Veterinary Medicine, 1992Co-Authors: Urasri Tantaswasdi, Jintana Danvivatanaporn, Porntip Siriwan, Arunee Chaisngh, P. B. SpradbrowAbstract:Laboratory chickens were vaccinated against Newcastle Disease by feeding them with the avirulent, heat-resistant V4 strain of Newcastle Disease virus applied to various grains. In one experiment, chickens receiving vaccine on paddy (unhusked) rice and on cooked white rice at 4 and 6 weeks of age were protected against contact challenge with a viscerotropic, velogenic strain of Newcastle Disease virus. The vaccine virus spread to in-contact chickens and these also resisted challenge. In another experiment, chickens receiving the same vaccine on the same grains were not projected. The chickens in the unsuccesful trial were younger, had higher levels of maternal antibody and were kept on wire mesh instead of on solid floors, thereby minimizing transmission of the vaccine virus. Strain V4 was an effective vaccine when given intranasally or in drinking water but V4 vaccine supplied on uncooked white rice and on uncooked broken brown rice was not protective. Oral vaccine delivered on paddy or cooked white rice could provide a practical method of protecting free-range village chickens against Newcastle Disease.
Cheng Lei - One of the best experts on this subject based on the ideXlab platform.
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Isolation and biological characteristics of Newcastle Disease virus in ostriches.
Chinese journal of veterinary science, 2000Co-Authors: Chen Changhai, Cheng LeiAbstract:Two strains of Newcastle Disease virus were isolated from ostriches suspected of having Newcastle Disease and idetified as Newcastle Disease virus with hemagglutination test (HA), hemagglutination-inhibition test (HI), monoclonal antibody against NDV PEG sandwich ELISA. The MDT of strain OJ99105 in 9-day-old SPF chicken embryos was 54 h, ICPI in 1-day-old SPF chickens was 1.88, IVPI in 6-week-old SPF chickens was 2.75. The results indicated that the NDV isolate OJ99105 should be a virulent strain.
D. Ben-nathan - One of the best experts on this subject based on the ideXlab platform.
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Newcastle Disease vaccines.
Biotechnology advances, 1998Co-Authors: Gilad E. Gallili, D. Ben-nathanAbstract:Newcastle Disease (ND) is a worldwide problem with severe economic implications, affecting chickens, turkeys and other birds. Newcastle Disease virus (NDV), a member of the Paramyxoviridae group can cause Disease of diverse severity in accordance with environmental factors. NDV strains are classified according to their virulence into three categories. The lentogenic strains are very mild and naturally inhabit healthy flocks. They can be used as live vaccines even for young chicks. Killed vaccines can be produced from the same viruses following inactivation. Mesogenic ND viruses, which cause mild or inapparent respiratory infections, have recently been banned in many countries even for killed vaccine production due to fears of Disease emergence. Velogenic strains are the causative agents of the Disease and can be used for the purpose of vaccine challenge test. Production and use of Newcastle Disease vaccines are discussed in this review.
Chen Changhai - One of the best experts on this subject based on the ideXlab platform.
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Isolation and biological characteristics of Newcastle Disease virus in ostriches.
Chinese journal of veterinary science, 2000Co-Authors: Chen Changhai, Cheng LeiAbstract:Two strains of Newcastle Disease virus were isolated from ostriches suspected of having Newcastle Disease and idetified as Newcastle Disease virus with hemagglutination test (HA), hemagglutination-inhibition test (HI), monoclonal antibody against NDV PEG sandwich ELISA. The MDT of strain OJ99105 in 9-day-old SPF chicken embryos was 54 h, ICPI in 1-day-old SPF chickens was 1.88, IVPI in 6-week-old SPF chickens was 2.75. The results indicated that the NDV isolate OJ99105 should be a virulent strain.
