خيارات البحث
النتائج 111 - 120 من 616
Mineral status in blood serum of newborn calves in Assiut Governorate النص الكامل
2009
M. A. Mohammad
The dynamics of some serum mineral concentrations during the first weeks of life of native and crossbred newborn calves in Assiut governorate were investigated. Blood samples of 25 Balady and 25 crossbred (Friesian x native) male calves were investigated. Blood was drawn from calves at 1, 7, 14 and 21 days after parturition. Serum levels of calcium (Ca), phosphorous (P), magnesium (Mg), sodium (Na), chloride (Cl), potassium (K), iron (Fe), Copper (Cu) and zinc (Zn) were monitored. Levels of Ca, P, Fe, Cu and Zn increased (P < 0.05) in relation to age of Balady and crossbred calves when compared by the day 1 of age. In contrast, decreased in concentrations of Na and Cl (P < 0.05) in relation to age of Balady and crossbred calves when compared by the day 1 of age were detected whereas Mg and K values remained unchanged. Native calves had higher (P < 0.05) Ca, P and Fe in the 7th day than crossbred calves whereas Na and Cl were higher (P < 0.05) in native calves than crossbred calves at the first day after birth. Results from this study suggested that breed and age may play an important role in mineral homeostasis during the first weeks of life in the newly borne bovine calves.
اظهر المزيد [+] اقل [-]Improved management of drugs, hormones and pesticides in Africa : policy and trade issues النص الكامل
2009
E.S. Mitema
Drugs, hormones and pesticides are chemical compounds used for alleviation of various diseases in animals. There are many classes of drugs which have been used and in the case of natural steroid hormones these have been used to increase mass gain by stimulating protein anabolism. Pesticides have been used for many years in the control of ectoparasites which transmit important human and livestock diseases. The purpose of the present article is to review procedures for management of veterinary products to facilitate national and international trade.
اظهر المزيد [+] اقل [-]Contagious bovine pleuropneumonia (lungsickness) in Africa : historical overview : Onderstepoort and veterinary research in Africa النص الكامل
2009
W. Amanfu
Contagious bovine pleuropneumonia (CBPP) or lung sickness, is an insidious pneumonic disease of cattle caused by Mycoplasma mycoides subspecies mycoides small colony variant (MmmSC) and it is one of the major diseases affecting cattle in Africa. With the imminent eradication of rinderpest from Africa (Somali ecosystem) CBPP has become the disease of prime concern in terms of epizootics that affect cattle on the continent. The control and/or eradication of the disease have suffered from unsustained control actions due to lack of operational funds to support such actions and deterioration in the quality of veterinary services in many countries affected by the disease. Stamping out procedures which were adopted by Botswana to control the disease (1995-1997) cannot be carried out by many countries currently affected by CBPP due to the high financial cost, the widespread nature of disease, animal welfare considerations and the potential loss of a valuable genetic resource base. The current scenario of CBPP disease epidemiology in sub-Saharan Africa requires that proactive measures are taken to safeguard countries in southern Africa which are currently free from CBPP from being contaminated by the disease thus affecting the beef industry and people's livelihoods ; and to progressively control the disease in endemic zones of Western and Central Africa.
اظهر المزيد [+] اقل [-]Assessing the economics of animal trypanosomosis in Africa-history and current perspectives النص الكامل
2009
Shaw, A.P.M.(A P Consultants)
Finding appropriate ways of dealing with the problem of tsetse and trypanosomosis will be an important component of efforts to alleviate poverty in Africa. This article reviews the history of economic analyses of the problem, starting with the use of cost to guide choice of technique for tsetse control in the 1950s, followed by work in the 1970s and 1980s linking these to the impact of the disease on livestock productivity, and in the 1990s to its wider impact. In the current situation, with limited resources and a range of techniques for controlling or eliminating tsetse, the cost implications of choosing one technique or another are important and a recent study reviewed these costs. A novel approach to assessing the potential benefits from removing trypanosomosis by creating 'money maps' showed that high losses from animal trypanosomosis currently occur in areas with high cattle population densities on the margins of the tsetse distribution and where animal traction is an important component of farming systems. Given the importance of the decisions to be made in the next decade, when prioritising and choosing techniques for dealing with tsetse and trypanosomosis, more work needs to be done underpinning such mapping exercises and estimating the true cost and likely impact of planned interventions.
اظهر المزيد [+] اقل [-]Tsetse and trypanosomosis in Africa: The challenges, the opportunities النص الكامل
2009
Ilemobade, A.A.(Upline Resources Foundation)
Tsetse-fly and the disease it transmits, trypanosomosis, remain an enormous disease challenge in the 37 countries of sub-Saharan Africa where the impact continues to be manifest in disease burden, increased level of poverty and decreased agricultural productivity. The impact also extends over an estimated 10 million km² (a third of the African continent) of land area, a third of which contains some well-watered part of the continent, thus denying humans and livestock of potentially rich arable and pastureland. The disease is a threat to an estimated 50 million people and 48 million cattle with estimated annual losses in cattle production alone of 1-1.2 billion US$. These losses are due to stock mortality and depressed productivity, which may be of meat, milk, reproduction or traction. Beyond its direct effects on humans and livestock is its impact on African agriculture and the livelihood of the rural population in the affected countries: the fly and the disease influence where people decide to live, how they manage their livestock, and the intensity and the mix of crop agriculture. The combined effects result in changes in land use and environment which may, in turn, affect human welfare and increase the vulnerability of agricultural activity. Trypanosomosis is, therefore, both a public health and an agricultural development constraint. The challenges that the elimination or control of tsetse fly and trypanosomosis pose as well as the opportunities to develop appropriate intervention technologies are discussed in this presentation.
اظهر المزيد [+] اقل [-]Persistence mechanisms in tick-borne diseases النص الكامل
2009
Barbet, A.F.(University of Florida College of Veterinary Medicine Department of Infectious Diseases & Pathology)
The use of new, highly sensitive diagnostic methods has revealed persistent infections to be a common feature of different tick-borne diseases, such as babesiosis, anaplasmosis and heartwater. Antigenic variation can contribute to disease persistence through the continual elaboration of new surface structures, and we know in several instances how this is achieved. Known or suspected mechanisms of persistence in babesial parasites include cytoadhesion and rapid variation of the adhesive ligand in Babesia bovis and genetic diversity in several merozoite stage proteins of different Babesia spp. In Anaplasma, extensive variation in the pfam01617 gene family accompanies cycling of organism levels in chronic infection. One result from the pioneering research at Onderstepoort is the definition of a related polymorphic gene family that is likely involved in immunity against heartwater disease. We are beginning to understand the sizes of the antigenic repertoires and full definition is close, with the possibility of applying simultaneous high-throughput sequencing to the order of 1 000 small genomes. We also, for the first time, can consider modifying these genomes and looking at effects on persistence and virulence. However, important biological questions remain unanswered; for example, why we are seeing a new emerging Anaplasma infection of humans and is infection of endothelial cells by Anaplasma significant to persistence in vivo.
اظهر المزيد [+] اقل [-]Sir Arnold Theiler and the discovery of anaplasmosis: A centennial perspective النص الكامل
2009
Palmer, G.H.(Washington State University School for Global Animal Health Department of Veterinary Microbiology and Pathology)
Sir Arnold Theiler's research in 1908/09 led to the discovery of the first rickettsial pathogen, Anaplasma marginale, and set the stage for his development and implementation of an effective live vaccine based on a less virulent strain, A. marginale ss. centrale. His 1910 report, describing A. marginale, is among the classic monographs in infectious disease research, presenting not only observations in exacting detail but also highlighting the deductive reasoning leading to association of a new pathogen with a specific disease. With a centennial perspective and both conceptual frameworks and molecular tools unimaginable in Theiler's time, the significance of several observations in the original report- cyclic bacteremia, strain superinfection, and taxonomic position-is now clear and highlight the broad applicability of key principles of pathogen biology.
اظهر المزيد [+] اقل [-]Veterinary education in Africa: Current and future perspectives النص الكامل
2009
Swan, G.E.(University of Pretoria Faculty of Veterinary Science) | Kriek, N.P.J.(University of Pretoria Faculty of Veterinary Science)
Veterinary education commenced in South Africa in 1920 at the Onderstepoort Veterinary Institute in South Africa in association with the Transvaal University College, now the University of Pretoria. Sir Arnold Theiler, Director of Veterinary Research and Education, was the first Dean. Today there are 46 veterinary training institutions in Africa of which 21 are in sub-Saharan Africa. Veterinary services are indispensable to the sustained health and wellbeing of animals and humans, and agricultural economies of countries worldwide. Veterinary education, postgraduate training, and research, and adequate numbers of veterinarians, are essential to satisfy the millennium development goals, the objectives of NEPAD and the African Union, and the agreements regulating international trade. The relevance of the veterinary profession internationally is currently subject to profound scrutiny. Its contributions are assessed against major environmental, demographic, political, disease, technological and economic needs. The scope of veterinary training in future will have to emphasise veterinary public health, food safety, emerging diseases, international trade, bioterrorism, and biomedical research, within the context of a one-health system focusing on the interface between wildlife, domesticated animals, humans, and their environment. Within the context of time available, it would mean reducing the time allocated to training in the field of companion animals. A brief history and scope of veterinary education; current international trends in veterinary education and provisioning; and some perspectives on future veterinary training and initiatives applicable to Africa are provided.
اظهر المزيد [+] اقل [-]Field services: Eradication and control of animal diseases النص الكامل
2009
Modisane, B.M.(Disaster Management and Veterinary Services National Department of Agriculture)
Prevention, eradication and control of animal diseases, as well as public health assurance are major functions of veterinary authorities. The strategies to control animal diseases differ from disease to disease but are often similar on a disease basis from country to country depending on the main objective of the measure employed. These measures include among others movement control and quarantine, vaccination, treatment and mass slaughtering. However, not every country uses all these control measures at the same time. A combination of measures may be employed to avoid spreading of the disease from infected to clean animals and success is dependent on a variety of factors, including the strength and capacity of the veterinary services, cross border efforts for disease surveillance, political will, diagnostic facilities and financial support.
اظهر المزيد [+] اقل [-]Molecular monitoring of African swine fever virus using surveys targeted at adult Ornithodoros ticks: A re-evaluation of Mkuze Game Reserve, South Africa النص الكامل
2009
Arnqt, L.F.(University of Pretoria Department of Zoology and Entomology Mammal Research Institute,University of Pretoria Faculty of Veterinary Science Department of Paraclinical Sciences) | Du Toit, J.T.(University of Pretoria Department of Zoology and Entomology Mammal Research Institute,Utah State University Department of Wildland Resources) | Bastos, A.D.S.(University of Pretoria Department of Zoology and Entomology Mammal Research Institute,ARC-Onderstepoort Veterinary Institute)
The Mkuze Game Reserve (MGR), in north-eastern KwaZulu-Natal Province, South Africa is an African swine fever virus (ASF) controlled area. In a survey conducted in 1978, ASF prevalence in warthogs and Ornithodoros ticks in MGR was determined to be 2 % and 0.06 %, respectively. These values, acknowledged as being unusually low compared to other East and southern African ASF-positive sylvatic-cycle host populations, have not been assessed since. The availability of a sensitive PCR-based virus detection method, developed specifically for the sylvatic tampan host, prompted a re-evaluation of ASF virus (ASFV) prevalence in MGR ticks. Of the 98 warthog burrows inspected for Ornithodoros presence, 59 (60.2 %>) were found to contain tampans and tick sampling was significantly male-biased. Whilst gender sampling-bias is not unusual, the 27 °% increase in infestation rate of warthog burrows since the 1978 survey is noteworthy as it anticipates a concomitant increase in ASFV prevalence, particularly in light of the high proportion (75 %>) of adult ticks sampled. However, despite DNA integrity being confirmed by internal control amplification of the host 16S gene, PCR screening failed to detect ASFV. These results suggest that ASFV has either disappeared from MGR or if present, is localized, occurring at exceptionally low levels. Further extensive surveys are required to establish the ASFV status of sylvatic hosts in this controlled area.
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