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1
Wright, Ashley D. "Clostridial Diseases of Cattle". College of Agriculture, University of Arizona (Tucson, AZ), 2016. http://hdl.handle.net/10150/625416.
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4 pp.Vaccinating for clostridial diseases is an important part of a ranch health program. These infections can have significant economic impacts on the ranch due to animal losses. There are several diseases caused by different organisms from the genus Clostridia, and most of these are preventable with a sound vaccination program. Many of these infections can progress very rapidly; animals that were healthy yesterday are simply found dead with no observed signs of sickness. In most cases treatment is difficult or impossible, therefore we rely on vaccination to prevent infection. The most common organisms included in a 7-way or 8-way clostridial vaccine are discussed below. By understanding how these diseases occur, how quickly they can progress, and which animals are at risk you will have a chance to improve your herd health and prevent the potential economic losses that come with a clostridial disease outbreak.
2
Tortosa, Christina Suzanne. "Reproductive diseases of dairy cattle /". Click here to view, 2009. http://digitalcommons.calpoly.edu/dscisp/6.
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Thesis (B.S.)--California Polytechnic State University, 2009.Project advisor: Edwin Jaster. Title from PDF title page; viewed on Jan. 21, 2010. Includes bibliographical references. Also available on microfiche.
3
Akpavie, Stephen Owarioro. "Globule leucocytes and respiratory diseases in cattle". Thesis, University of Glasgow, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254183.
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Elliott, Malcolm Gordon, of Western Sydney Hawkesbury University y Faculty of Environmental Management and Agriculture. "Grass tetany of cattle in New South Wales". THESIS_FEMA_xxx_Elliott_M.xml, 2000. http://handle.uws.edu.au:8081/1959.7/7.
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Over the last 60 years, grass tetany has been recognised as a significant lethal condition in sheep and cattle.Outcomes from this study include documentation of the likely precursors to grass tetany, ways to recognise these precursors, and long term practices that will enable producers to minimise livestock deaths. The benefit of this research to beef producers is that the environmental circumstances thought to be associated with outbreaks of grass tetany have been identified, along with remedial action that can be taken to prevent deaths occurring.Recommendations to industry on best practice to be adopted by leading producers to minimise outbreaks of grass tetany are made.This study provides an alternate strategy for the management of grass tetany in beef cattle, to the more clinical approaches previously recommended. It is suggested that losses from this economically important metabolic disease can be minimised if management practices of beef cattle producers in eastern Australia can incorporate a more holistic approach to farm management, which takes account of the soil/plant/animal/climate inter-relationships.Master of Science (Hons)
5
Biswal, Jitendra Kumar. "Evaluation of mucosal immunity in FMDV vaccinated and infected cattle". Thesis, Royal Veterinary College (University of London), 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572448.
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Windsor, Peter A. "The pathogenesis of genetic and infectious disorders acquired between conception and the immediate post-partum period in sheep and cattle". Phd thesis, Faculty of Veterinary Science, 2007. http://hdl.handle.net/2123/4120.
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Motta, Paolo Roberto. "Characterisation and modeling of cattle movements in Cameroon". Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/28767.
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Introduction In sub-Saharan Africa, rapid urbanisation and per capita consumption of animal source foods are expected to accelerate in the short-medium term and to increase the movements of live animals and animal products in the region. In Cameroon, where the livelihood of most of the rural population depends on the agricultural and livestock sector, a wide range of endemic transboundary infectious diseases (TADs) affect livestock production and trade, and have direct detrimental effects on animal, human and environmental health. Livestock mobility represents a central economic activity in the livestock value chain of the country as well as a central strategy of seasonal adaptation to the ecosystem. Livestock movements, however, are also a central driver of infectious diseases dynamics and contacts between livestock populations are major risk factors for disease introduction and circulation. In countries where financial and technical resources are constrained, such as Cameroon, strategic interventions aiming at the surveillance and control of multiple infectious diseases simultaneously are essential for optimising their cost-effectiveness. The overall aim of this study was to apply a methodological framework to contribute to the understanding of cattle movements in Cameroon and of their implications for disease circulation. Methods This project used a variety of epidemiological and statistical methods to characterise cattle movements in the country across different scales. The collection of primary data and information targeted both the formal cattle trade system, across the country, and the informal seasonal transhumance, across the main livestock production areas. Between September 2014 and May 2015 diverse strategies were applied for collecting empirical data and various data sources from multiple Regions of the country were combined. Cattle trade in Cameroon mainly occurs via multiple trading points owned and managed either by the veterinary authorities or the municipalities. A total of 62 livestock markets, and the relevant offices of the Ministry of Livestock, Fisheries and Animal Products (MINEPIA), were targeted for collecting official data on cattle trade referring to a 12-month period ranging between September 2013 and August 2014. Additionally, a questionnaire-based survey with the various livestock markets stakeholders (herders, traders, butchers and veterinary officials) was carried out to collect a variety of information on the cattle market system. During this 9-month period of field work, data on cattle seasonal transhumance were simultaneously collected using a combination of GPS-tracking technology and questionnaire-based survey. Results Volumes of cattle trade, the type of traded animals and their commercial values varied over the year and across the Regions of the country included in this study. Nevertheless, the market supply of live cattle showed similar temporal trends over the year and across the Regions. Although for almost the entire study area the peak of traded animals in the market system was in December 2013, the trade volume was consistently higher during the rainy season (May to September). On the contrary, the reduction in the trade volume during the dry season was accompanied by an opposite trend in the cattle price, with their commercial value being higher during the dry season. Furthermore, a cattle price differential was highlighted between production Regions and high consumption Regions of the country. The highest volume of cattle trade was recorded in the Adamawa Region, which was the main source of cattle for the country while also receiving animals from neighbouring countries, such as Chad and Central African Republic. In contrast, major urban markets in the Littoral and Central Regions were the main receivers of cattle originating from almost all the other areas of the country. Interestingly, the North-West Region appeared to be more independent and isolated within the cattle trade network of Cameroon, particularly receiving few animals from other Regions. Importantly, there was little variation in the structural characteristics of the cattle trade network as well as in its properties across seasons, showing that, despite the seasonality in traded numbers, the network of cattle moving between markets in Cameroon is very stable. This consistent structure of the network over the year increases the robustness of strategic targeted interventions. We found that targeting the top 20% of the most connected markets would significantly reduce the network cohesiveness providing opportunities for strategic disease surveillance, communication and risk mitigation interventions. The centrality of the market within the trading network was also found to be positively associated with the price of live cattle, which tended to be heavily affected by phenotypic characteristics of the traded cattle. The seasonal cattle transhumance has been found as a common and widespread practice for herders attending the market system across whole the study area, highlighting the close relation between formal trading movements and informal pastoral movements across the country. Transhumant herds were observed to undertake migrations across multiple Regions for period exceeding 6 months and showing the potential for multiple types of interactions with domestic and wild animals. Discussion Multiple livestock infectious diseases were identified as being related to the cattle trade system. As neighbouring and non-neighbouring countries were found to be epidemiologically connected it is clear that national strategies for surveillance and control are likely to have limited effectiveness. Regional coordination for designing and implementing prevention and mitigation strategies against infectious diseases is essential to improve animal health also at national level. This study highlights the opportunity for strategic surveillance, control and communication interventions targeting key livestock markets and Regions of Cameroon. Live cattle price and centrality of markets, represented by their connectedness within the trading network, highlights the need to further investigate the links between economic factors and drivers of disease dynamics, such as livestock movements. The complexity of cattle movements in this context was further evidenced by the seasonal transhumance representing an established common mechanism for managing livestock, and closely interacting with the formal trading system as well as with other domestic and wild animal populations. Better data collection and analysis of livestock movements is required for improving the effectiveness of surveillance and control of infectious diseases. Although animal identification and registration systems would represent an ideal step for increasing traceability of cattle movements, enhancing animal health management and the overall competitiveness of the livestock industry, in the short-term a cost-effective intervention should aim at further developing the current data recording and management systems. Pastoralism, for long seen as an economic and environmental activity with little future, also needs to be acknowledged as a key component of the livestock production system in the country and to be considered accordingly in the management of infectious diseases.
8
McOdimba, Francis Awuor. "Epidemiology of vector-borne diseases in cattle from SE Uganda". Thesis, University of Edinburgh, 2006. http://hdl.handle.net/1842/30498.
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Institutions involved in vector-borne diseases research, epidemiological studies as well as vaccine development require reliable and sensitive assays to support the development of vaccine products and new drugs for treatment. These diagnostic assays also aid in identifying disease control target populations, and to monitor infection during trials for assessing the efficacy of preventive or curative drug. Molecular techniques such as the polymerase chain reaction (PCR) amplification have been used in detecting parasites of several species, sub-species and types and are favoured over microscopic examination of blood or the immunological methods because of their superior sensitivity and higher throughput. Two of the most commonly used diagnostic methods, microscopy and molecular techniques for pathogen detection and species characterization, were evaluated for their sensitivity and specificity and subsequently used in screening cattle for parasites in the blood of cattle kept under traditional mixed farming management system. Molecular methods revealed higher VBD prevalence in the cattle from the villages of Tororo and Busia districts of SE Uganda. The prevalence of trypanosome species pathogenic to livestock was found to be higher than previously documented in this area. Based on the data obtained by PCR amplification the effect of prophylactic drug intervention against trypanosomiasis was assessed over a period of six months. While isometamidium chloride treatment of cattle appeared to control trypanosomiasis in areas with low prevalence, the drug had no effect in controlling the disease in high prevalence areas. It would therefore be necessary to combine the use of drug intervention with other methods such as vector control, to reduce the prevalence, in order to realize effective control of trypanosomiasis.
9
Li, Yihang Kaltenboeck Bernhard. "Therapeutic vaccines against chlamydial diseases". Auburn, Ala., 2008. http://hdl.handle.net/10415/1417.
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Mulongo, Musa Matsanza. "Evaluation of lipoprotein Q and L-a-glycerol-3-phosphate oxidase of mycoplasma mycoides subs. mycoides (small colony) as virulence factors in contagious bovine pleuropneumonia (CBPP) infections". Thesis, Royal Veterinary College (University of London), 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558979.
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Iqbal, Muhammad. "Studies on the use of DNA as an immunogen in bovine viral diarrhoea virus". Thesis, Royal Veterinary College (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272468.
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Brown, Graham Alfred. "A study of bovine herpesvirus 1 pathogenesis using laboratory models". Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304239.
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O'Connor, Michael. "Epidemiology of selected viral diseases of cattle and pigs in Ireland". Thesis, Oxford Brookes University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400354.
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Menzies, Fraser Duncan. "Epidemiological studies on economically important diseases of cattle in Northern Ireland". Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300778.
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Swangchan-Uthai, Theerawat. "Molecular response of the endometrium to bacterial infection in dairy cattle". Thesis, Royal Veterinary College (University of London), 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572492.
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Eriksson, Erik. "Verotoxinogenic Escherichia coli O157:H7 in Swedish cattle and pigs /". Uppsala : Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, 2010. http://epsilon.slu.se/201003.pdf.
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Pohl, Anna Elisabeth. "Epidemiology study of tick-borne diseases in cattle in Minas Gerais, Brazil". Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-161003.
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The study aimed to characterize the occurrence of tick-borne diseases within a herd in an endemic region in Brazil, focusing on two different aspects:
(a) to determine the occurrence of the three pathogens Anaplasma marginale, Babesia bovis and Babesia bigemina using direct and indirect detection methods and
(b) to analyze the incidence of genetic diversity among A. marginale isolates based on a Major Surface Protein (MSP) as a marker of variation within the farm.
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Busato, André. "The epidemiology of production diseases in Swiss dairy and beef cattle herds /". Bern : [s.n.], 2000. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Rezac, Darrel James. "Gross pathology monitoring of cattle at slaughter". Diss., Kansas State University, 2013. http://hdl.handle.net/2097/16386.
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Doctor of PhilosophyDepartment of Diagnostic Medicine/Pathobiology
Daniel U. Thomson
A series of studies were conducted in order to develop, test, implement, and utilize an objective and comprehensive gross pathology scoring system for cattle at slaughter. Individual lung, liver, and rumen gross pathology data was collected from 19,229 head of cattle and corresponding individual pre-harvest and carcass data for a subset of 13,226 head.. Across the entire population 22.6% and 9.8% of cattle displayed mild and severe lesions, respectively. Severe lung lesions at the time of slaughter were associated with a decreased ADG of 0.07 kg/ day and a carcass weight 7.1 kg less than that of their cohorts with no visible signs of pulmonary BRDC lesions (P < 0.01). Overall, 68.6 % of cattle observed had normal livers, free from abscesses and other abnormalities. Cattle with a severe liver abscess at the time of slaughter were associated with a 0.10 kg/day during the feeding period (P < 0.01). Of cattle severely affected by liver abscesses (A+, 4.6%), 14.9% also displayed severe BRDC lung lesions and 28.3 % of cattle displayed mild BRDC lung lesions. Rumenitis lesions were observed in 24.1% of the overall study population. Severe rumenitis lesions were associated with a significant decrease in average daily gain and carcass weight (0.03kg/day and 2.20 kg, respectively, P < 0.01). The system was also implemented on a population of cull cows at a commercial abattoir in the Great Lakes region of the U.S. (n=1,461; 87% Holstein, 13% other cows). Severe liver abscesses, were observed in 18.5% of cull cows at slaughter. Severe rumenitis lesions or rumenitis scars were observed in 10% and severe BRDC lesions were observed in 10.3% o of the population. A prospective study of a commercially available, direct fed microbial oral drench of Megasphaera elsdenii (NCIMB 41125) was conducted in 4,863 head of yearling feeder cattle. No significant effects of treatment were detected for final live weight (599 vs. 601 kg; P=0.79) or hot carcass weight (386 vs. 387 kg P=0.81) for Con and M.e., respectively. Fourteen point two percent and 14.0% of Con and M.e., respectively displayed a liver abscess of varying severity at the time of slaughter. Overall, 8.27 and 7.96% % of Con and M.e. cattle were observed with an altered rumen epithelial health status. The ordinal odds ratio of a M.e. treated animal having a more severe liver abscess score or rumen health score was not significant (Estimate: 0.96, 95% C.L. 0.733-1.259, P=0.771; Estimate: 1.01, 95% C.L. 0.625-1.63 P=0.96, respectively.) Comprehensive monitoring of gross pathology at slaughter is commercially plausible and provides valuable data for veterinarians, nutritionists and management personnel.
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au, w. ditcham@murdoch edu y William Ditcham. "The development of recombinant vaccines against Jembrana disease". Murdoch University, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20071119.94111.
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Jembrana disease virus (JDV) is a lentivirus causing an acute infection with a 17% case fatality rate in Bali cattle in Indonesia. Control of the disease is currently achieved by identification of infected areas and restriction of cattle movement. A detergent-inactivated whole virus tissue-derived vaccine is sometimes employed in affected areas.
This thesis reports initial attempts to produce genetically engineered vaccines to replace the inactivated tissue-derived vaccine, which as it is made from homogenised spleen of infected animals, is expensive to produce and could contain adventitious agents present in the donor animals.
4 potential DNA vaccine constructs were created containing the JDV genes coding for the Tat, capsid (CA), transmembrane (TM) and surface unit (SU) proteins in a commercially available vaccine plasmid. These were assessed for functionality in a range of in vitro and in vivo assays. All proteins were expressed in vitro and administration of 2 of the constructs by a commercial gene gun into the epidermis of mice resulted in antibody production to the appropriate protein. Due to the difficulties of licensing such a DNA vaccine in Indonesia, these vaccines were not progressed further.
A mathematical model was developed to describe the progression of the acute phase of Jembrana disease following experimental infection with JDV. The model divided the disease into 6 phases based on the rates of viral replication and clearance calculated from data on sequential plasma viral RNA load detected by quantitative reverse-transcription polymerase chain reaction. This allowed statistical comparison of each phase of the disease and comparison of the severity of the disease process in groups of animals. The use of the model overcame the difficulty of comparing the disease in different animals as a consequence of the animal-to-animal variation in the disease process.
The mathematical model was used to identify differences in the pathogenicity of 2 strains of JDV. One strain, JDVTAB caused a more rapid onset of disease in non-vaccinated controls, a significantly higher virus load at the onset of the febrile period and a higher peak viraemia than in animals infected with JDVPUL. This provided the first evidence of variation in pathogenicity of JDV strains.
The measurement of virus load also demonstrated that some JDV infected animals developed a clinical disease that was not typical of that which had been reported previously. When infected with less than 1,000 infectious virus particles, up to 20% of infected animals failed to develop a febrile response. Infection of these animals was confirmed, however, by the detection of a high titre of circulating virus particles in plasma. These atypical infections had not been reported previously.
Application of the mathematical model describing the progression of the disease in individual animals was used to examine the effect of vaccination with the inactivated tissue-derived vaccine on the progression of the disease. Several effects were noted in vaccinated animals that were subsequently infected with JDV: a reduction in the duration of the febrile response, a reduction in the severity of the febrile response in the early phases of the acute disease, and a reduction in virus load in the early and later phases of the disease process.
The effect of vaccination with recombinant Tat, matrix (MA) and CA protein vaccines expressed in a bacterial expression system on subsequent JDV infection was also examined. A vaccine incorporating recombinant Tat and CA vaccine emulsified with Freunds incomplete adjuvant decreased the febrile response particularly in the later stages of the acute disease process, decreased the severity of the leucopenia in the later phases of the acute disease, and decreased the virus load in some but not all phases of the acute disease process. Vaccines administered with Freunds incomplete adjuvant were more efficacious than vaccines administered with QuilA, the latter actually exacerbating the disease process in vaccinated animals.
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O'Brien, John Kieran. "Interactions between bovine leucocytes and respiratory pathogens". Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254519.
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Lutje, Vittoria. "Proliferative and antibody responses induced by pokeweed mitogen, sheep erythrocytes and ovalbumin in bovine leukocyte populations and the cellular interactions involved". Thesis, Brunel University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280691.
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Edwards, Steven. "Infectious bovine rhinotracheitis in Great Britain". Thesis, University of Edinburgh, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236104.
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Kalthoff, Cynthia Ellen 1962. "THE PATHOGENICITY OF MORAXELLA BOVIS IN SEVERAL STRAINS OF MICE". Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/277214.
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Ferreira, Gert Marthinus. "The prevalence of bovine viral diarrhoea antibodies in selected dairy herds and the use of serology in the control of the disease". Pretoria : [s.n.], 1997. http://explore.up.ac.za/record=b1411078.
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Marcé, Clara L. H. "Modelling the transmission of and effectiveness of control measures for Mycobacterium avium subsp. paratuberculosis in dairy herds". Thesis, Royal Veterinary College (University of London), 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558974.
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Clempson, Andrew. "Associations of genetic polymorphisms with growth, fertility and production traits in UK dairy cattle". Thesis, Royal Veterinary College (University of London), 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558960.
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Al-Abri, Mohammed Ali. "Genetic variability of health disorders in Ontario Holstein cows". Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112310.
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Extensive emphasis on selection for milk yield with minimal attention to the animals' functional performance has increased the yield of North American dairy cattle. The high intensity of selection for production traits such as milk yield, protein yield and fat yield has also brought about a rapid increase in genetic relationships among animals. In dairy cattle, correlated response to selection for milk yield includes fertility and susceptibility to diseases. Although the high producing cows have greater net profit, they also have higher mammary and discarded milk costs associated with high production. Long-term genetic selection against clinically diagnosed diseases might be useful to diminish their incidence. The Scandinavian countries have incorporated the health traits into their selection indices. Canadian breeding programs realize the need to consider traits other than the yield in selection decisions. The objective of this study was to determine the genetic variability of various clinically diagnosed health traits. Data from 171 herds of the Ontario milk-recording program were used. These herds are collaborating with the University of Guelph (Dr. David Kelton) to record health traits. A major impediment to estimating heritabilities for the majority of the disorders was that the progeny group size per sire was not large enough to enable detecting a significant difference among sires. Hence, heritability estimates were not obtained for all the health disorders included in the study. The progeny group size per sire has to be increased such that there are at least 5 cases per progeny group to enable detecting a difference among sires. Heritability estimates for retained placenta and displaced abomasum in the first lactation were 0.067 and 0.212 respectively. The heritability estimate of cystic ovaries in the second lactation was 0.092. In the third lactation, the heritability estimate of mastitis was 0.10 whereas retained placenta had a heritability of 0.25.
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Tembo, Stephen. "Occurrence of tick-borne haemoparasites in cattle in the Mungwi district, Northern Province, Zambia". Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/26218.
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The most important tick-borne diseases (TBDs) occurring in Zambia that affect domestic animals, particularly cattle and small ruminants, are theileriosis (East Coast fever and Corridor disease), anaplasmosis (gall sickness), babesiosis (red water), and heartwater (cowdriosis). Of these, theileriosis is the most important, causing significantly more deaths than the other tick-borne diseases combined. Despite their importance, little is known about the occurrence and prevalence of haemoparasites in cattle in the communal areas of Zambia. Clinical signs and post mortem lesions are pathognomonic of mixed tick-borne infections especially babesiosis, anaplasmosis and East Coast fever (ECF). The main objective of this study was, therefore, to screen selected communal herds of cattle for tick-borne haemoparasites and identify the tick vectors associated with the high cattle mortalities due to suspected TBDs in the local breeds of cattle grazing along the banks of the Chambeshi River in Mungwi, Zambia. East Coast fever is endemic to the district of Mungwi, Northern Province, Zambia and vector control using acaricides has proved to be very costly for the small scale farmers. Also, Mungwi experiences increased cattle mortalities between December to March and May to July. All age groups of cattle are affected. A total of 299 cattle blood samples were collected from July to September 2010 from Kapamba (n=50), Chifulo (n=102), Chisanga (n=38), Kowa (n=95) and Mungwi central (n=14) in the Mungwi District, Northern Province, Zambia. Ticks were also collected from the sampled cattle from April to July 2011. DNA was extracted and the parasite hypervariable region of the small subunit rRNA gene was amplified and subjected to the reverse line blot (RLB) hybridization assay. The results of the RLB assay revealed the presence of tick-borne haemoparasites in 259 samples occurring either as single or mixed infections. The most prevalent species present were the benign Theileria mutans (54.5%) and T. velifera (51.5%). Anaplasma marginale (25.7%), Babesia bovis (7.7%) and B. bigemina (3.3%) were also detected in the samples. Nine percent of the samples tested negative for the presence of haemoparasites. In a number of samples (4%) the PCR products failed to hybridize with any species-specific probes but hybridized only with the genus-specific probes which could suggest the presence of a novel species or variant of a species. Of the four Theileria species known to occur in Zambia (T. parva, T. mutans, T. velifera and T. taurotragi), T. parva is the most economically important, causing Corridor disease in the Southern, Central, Lusaka and the Copper-belt provinces, while causing ECF in the Northern and Eastern provinces of Zambia. In our study, only one sample (from Kapamba) tested positive for the presence of T. parva. This was an unexpected finding; also because the tick vector, Rhipicephalus appendiculatus, was identified on animals from Kowa (14%), Chisanga (8.5%), Chifulo (6%) and Kapamba (1.4%). We can only speculate that the RLB hybridization assay may not have been able to detect the parasite in the animals sampled due to a too low parasitaemia. The samples should also be subjected to the T. parva specific real-time PCR assay to determine a more accurate T. parva prevalence in cattle in the Mungwi district, Northern Province. In Zambia, Babesia bovis and B. bigemina are recognized as being of economic importance in cattle. In our study, B. bovis was present in 7.7% of the sampled animals and B. bigemina in 3.3% of the animals. We detected B. bovis in all of the five sampled areas with the highest detection in Mungwi central (14.3%) and Kowa (10.5%). As expected, the tick vector Rhipicephalus (Boophilus) microplus was identified from animals from all of these areas. Babesia bigemina was only reported from Kowa (10.5%). The most abundant ticks identified from the sampled animals from Kowa were Rhipicephalus (Boophilus) decoloratus (36.3%) and Rhipicephalus (Boophilus) microplus (8.8%). These tick vectors have been implicated in the transmission of B. bigemina. Our findings are in concordance with results obtained by other authors who have speculated that an increase in the detection of B. bovis may indicate that B. bovis is becoming endemic in this part of the country. This could be due to uncontrolled movement of cattle that frequently occurs within Zambia. Heartwater (cowdriosis) is caused by Ehrlichia ruminantium, a rickettsial disease that affects domestic and wild ruminants. In Zambia, heartwater is mainly a disease of cattle, although outbreaks in sheep and goats have been reported and recorded. In our study, only one sample (from Kapamba) tested positive for the presence of E. ruminantium even though Amblyomma variegatum ticks were identified from 52.9% of the sampled animals from all study areas. The cattle sampled in our study are not regularly dipped and no game has been spotted in cattle grazing areas. It is possible that these cattle may have attained a state of endemic stability to heartwater. It is also possible that the RLB hybridization assay may not have been sensitive enough to detect E. ruminantium infections if the parasitaemia was very low. Samples should also be subjected to the E. ruminantium-specific pCS20 real-time PCR assay to determine more accurately the E. ruminantium prevalence in cattle in the Mungwi district, Northern Province. Anaplasma marginale (the causative agent of bovine anaplasmosis) has previously been shown to be present in all the provinces of Zambia and is the only Anaplasma species of importance to cattle in Zambia. In our study, 25.7% of the sampled cattle tested positive for A. marginale; it was detected in all areas except Chisanga. Amblyomma variegatum was identified from 52.9% of the sampled cattle, and Rhipicephalus (Boophilus) microplus from 12.1% of the cattle. Rhipicephalus (Boophilus) microplus has been incriminated as being a vector of A. marginale. Furthermore, three samples (from Kowa) tested positive for the presence of Anaplasma centrale. To our knowledge, no vaccination regime using A. centrale is being conducted in the Mungwi district of Zambia. The presence of A. centrale is, therefore, an interesting finding. The results of our study suggest that the cause of cattle mortalities in Mungwi during the winter outbreaks is mainly due to A. marginale, B. bovis and B. bigemina infections. This was confirmed by the results of the RLB hybridization assay, clinical manifestation of the disease in the affected cattle (own observation) and the tick species identified on the animals. It appears that in Mungwi, babesiosis due to B. bovis mostly infects cattle above one year of age. Calves appear to be less affected by B. bovis infection. There is need for further epidemiological surveys in Mungwi district, Northern Province, Zambia to get a better understanding of the epidemiology of these tick-borne haemoparasites affecting cattle. We conclude that integrated control policies should be developed to take account of multi-species pathogen communities that are commonly associated with clinical and sub-clinical TBD infections in Zambia.Dissertation (MSc)--University of Pretoria, 2012.
Veterinary Tropical Diseases
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Sianangama, Pharaoh Collins. "Effects of human chorionic gonadotropin administration at various times following breeding on corpus luteum number, diameter, progesterone profiles and pregnancy rates in dairy cattle". Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28745.
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Corpus luteum (CL) dysfunction has been implicated among various factors predisposing early embryonic mortality in cattle. Two experiments were conducted to evaluate the efficacy of using human chorionic gonadotropin (hCG) given either at the time of breeding (day 0) , day 7 or 14 post breeding, in reducing that component of early embryonic mortality caused by CL dysfunction. The aims of experiment 1 were to investigate the effectiveness of using hCG, in inducing the development of accessory CL, their formation and growth, and the effect of such treatments on the function of both the induced and spontaneous CL.
Thirty-four lactating Holstein cows were randomly assigned to one of four treatments. A single intramuscular injection of 1000 IU of hCG was given either at the time of breeding (day 0, n=8), day 7 (n=9) or 14 (n=9) post breeding or no hCG given (control, n=8). A real-time ultrasound machine was used to study follicular dynamics and CL growth. The CL and antral follicle diameter was determined using a built-in system of calibrated callipers. Ultrasound scanning was carried out on days 7, 9, 11, 14, 16, 18, 21, 28, 35 and 42 post breeding. Blood and milk samples, for progesterone (P₄) determination using radioimmunoassay, were collected on days coincident with ultrasonography. Diameter of the CL is presented as the sum of the diameter of all luteal tissue in each animal. Differences in CL diameter, milk and plasma P₄ were analyzed using the General Linear Models Procedures while pregnancy data were analyzed using Chi-Square analysis in Statistical Analysis Systems (SAS, version 6.3).
Based on the day 7 ultrasound scanning, the incidence of twin ovulations was higher among cows treated on day 0 (3/8) compared to control cows (1/8) and day 7 (1/9). Accessory CL were detected in 7/9 of the day 7-treated cows compared to 4/9 among the day-14 treated cows. Least squares means (LSMeans) for CL diameter were significantly higher (P<0.001) among cows treated with hCG compared to control cows starting at day 7 continually until day 42. Plasma P₄ profiles were significantly higher (P<0.05), at days 18, 35 and 42, in cows treated on day 7 or 14 compared to control cows. The first detectable differences (P<0.05) between hCG treated and control cows, in milk P₄ occurred at day 21 and persisted until day 42. Pregnancy rates were highest among cows treated with hCG on day 7 where 6 of the 9 cows were diagnosed pregnant. Corresponding pregnancy rates for day 0, 14 or control cows, were 4/8, 5/9 and 3/8, respectively.
In the second experiment, two trials were conducted at two different farms to investigate the efficacy of using hCG to increase milk P₄ and pregnancy rates. In trial one, 79 lactating Holstein cows were exposed to the treatment protocol described in experiment 1. In addition to the milk sample collection schedule given in experiment 1, a sample was collected on day 0. Milk samples were stored at 4°C and later transported to the UBC laboratories for P₄ analysis. LSMeans for milk P₄ concentrations were different only at days 16 and 18 post breeding. Pregnancy rates were improved (P<0.01) by hCG treatments. The respective pregnancy rates for cows receiving hCG on day 0 (n=20), 7 (n=20), 14 (n=20) or control (n=19) were 25, 35, 35 and 21 %.
In the second trial, 121 lactating Holstein cows were randomly assigned to treatments as described earlier. Weekly milk samples were collected from each animal and assayed for P₄ as described above. LSMeans for milk P₄ were significantly different (P<0.05) among groups starting at day 14 until day 42 post breeding. hCG increased pregnancy rates over control cows. The pregnancy rates for cows treated on day 0, 7, 14 and control were 31, 50, 41 and 26 %, respectively.
In conclusion, this study revealed that treatment with hCG induced accessory CL development, increased P₄ production and improved pregnancy rates. It is evident, too, that treatment with hCG on day 7 post breeding may have greater potential for improving pregnancy rates not only in dairy and beef cattle but equally beneficial to the embryo transfer programmes. Increased pregnancy rates confirm the hypothesis that CL dysfunction does cost the livestock industry appreciable losses in embryos.Land and Food Systems, Faculty of
Graduate
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Hegazy, Yamen Mohammed. "Ruminant brucellosis in Egypt : frequency, distribution and potential control strategies". Thesis, Royal Veterinary College (University of London), 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558965.
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Torres, Siddartha. "Various factors involved in control, treatment, and investigation of bovine respiratory disease in high risk feedlot cattle". Diss., Kansas State University, 2013. http://hdl.handle.net/2097/15315.
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Doctor of PhilosophyDepartment of Animal Science and Industry
Chris Reinhardt
Dan Thomson
Bovine Respiratory Disease Complex (BRDC) is the most common and costly disease in feedlot cattle in North America. Annual economic losses are estimated to be US$1 billion due to mortality, reduced performance, and treatment costs. The disease is a multifactorial syndrome caused by a combination of environmental factors, management practices, animal susceptibility, and viral and bacterial pathogens. The objectives of this dissertation were to evaluate two injectable antimicrobials for the treatment and control of BRDC in feedlot cattle, investigation of factors associated with BRDC mortality and morbidity, and to develop control charts based on statistical process control (SPC) principles to monitor cattle mortality rates. Two multi-site prospective studies were conducted to evaluate the comparative efficacy of the administration of gamithromycin and tulathromycin for the treatment and control of BRDC. A total of 2,529 animals were enrolled at two commercial feedlot locations to evaluate the efficacy of the antimicrobials to control BRDC. Morbidity due to BRDC was higher (P = 0.03) among calves receiving gamithromycin compared with those receiving tulathromycin; however, treatments were considered bioequivalent (P < 0.05) for BRDC mortality, case fatality rate and re-treatment rate. Final BW, ADG, DMI and F:G, were similar (P<0.05) between the groups of calves receiving gamithromycin and tulathromycin. For the evaluation of treatment efficacy, a total of 1,049 calves were enrolled in the study. Re-treatment rate was higher among animals treated with gamithromycin compared with those treated with tulathromycin. Treatments were bioequivalent (P < 0.05) for case fatality rate, final BW, and ADG. To evaluate factors associated with BRDC, a retrospective study was conducted to analyze BRDC mortality and morbidity associated with initial body weight, rectal temperature, and castration and dehorning (tipping) at processing. Calves with lighter weights and fever at processing were at greater risk of mortality and morbidity due to BRDC. Also, bulls castrated at processing were at higher risk of developing BRDC. Finally, we developed control charts based on SPC principles to monitor and identify “normal” and special cases of variation of mortality rate. In feedlot cattle, monitoring lots of cattle through SPC principles can be used as a powerful tool for continuous improvement.
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Suleiman, Abubakar. "Socioeconomic challenges of contagious bovine pleuropneumonia control in pastoral areas of north western Nigeria". Thesis, Royal Veterinary College (University of London), 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701673.
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Hägglund, Sara. "Epidemiology, detection and prevention of respiratory virus infections in Swedish cattle : with special reference to bovine respiratory syncytial virus /". Uppsala : Dept. of Clinical Sciences, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/2005121.pdf.
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Hesterberg, Uta Walburga. "A serological prevalence study of important infectious diseases of cattle in rural areas of Kwa Zulu Natal, South Africa". Diss., Access to E-Thesis, 2007. http://upetd.up.ac.za/thesis/available/etd-05062008-081645.
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Lessard, Pierre. "The application of computerized geographic information systems to epidemiological surveillance of cattle diseases caused by Theileria Parva". Diss., This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-08032007-102231/.
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Osuagwuh, Uchebuchi I. "Semen quality and the excretion of lumpy skin disease virus in semen following vaccination and experimental challenge of vaccinated bulls". Diss., University of Pretoria, 2006. http://hdl.handle.net/2263/23607.
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The aim of this study was to determine the efficacy of vaccination in preventing LSDV excretion in semen and negative effects on semen quality. Lumpy skin disease (LSD) is caused by a virus in the genus Capripoxvirus of the family Poxviridae. The virus has been reported to be excreted in the semen of experimental infected nonvaccinated bulls. Nevertheless, vaccination has been the most widely used method to reduce and prevent the spread of the disease. This work was done to determine the efficacy of lumpy skin disease vaccination in preventing the excretion of lumpy skin disease virus (LSDV) in semen of experimentally infected vaccinated bulls. It also determined further the effect of vaccination and experimental infection on semen quality. Six serologically negative bulls 11-16 months of age were vaccinated with an attenuated Neethling strain of LSD vaccine, and a repeated dose of vaccine was given twenty one days later. These bulls were then experimentally infected by intravenous injection with a virulent field strain of LSDV (V248/93). Six unvaccinated bulls were similarly infected to act as controls. All animals were observed for clinical signs, blood and semen was collected and evaluated twice a week until day 40 post vaccination and every two days until day 28 post-infection when the trial was terminated. Serology was done using the serum neutralization test and viraemia was determined by virus isolation. Semen was examined by polymerase chain reaction (PCR) for the presence of virus. Semen evaluation was done visually and microscopically. Two of the unvaccinated controls developed severe LSD, two showed mild symptoms and two were asymptomatic. No clinical abnormalities were detected following vaccination, and clinical signs were limited to mild lymph node enlargement in four bulls following challenge of the vaccinated bulls. There was a significant difference (P<0.05) in semen quality after experimental infection of the unvaccinated bulls. In the vaccinated bulls, semen quality showed no significant difference (P>0.05) following vaccination and challenge. Three of the vaccinated bulls were serologically positive at the time of experimental infection and four at the end of the trial. Five unvaccinated bulls were found to be viraemic during the course of the trial. No vaccinated bulls were found to be viraemic at any stage. Four unvaccinated bulls excreted the virus in their semen during the course of the trial. Viral nucleic acid was not detected in any semen samples following vaccination or challenge in vaccinated bulls. This study provides evidence that vaccination against LSD prevented the excretion of viral particles in semen. It also illustrated that LSD vaccination prevented any effect on semen quality after experimental infection with virulent virus.Dissertation (MSc (Production Animal Studies))--University of Pretoria, 2006.
Production Animal Studies
unrestricted
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Masgoret, Cuellar Maria Sol. "Molasses as a possible cause of "endocrine disruptive syndrome" in cattle". Diss., University of Pretoria, 2007. http://hdl.handle.net/2263/29274.
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The objective of this study was to evaluate the suspected endocrine disruptive effect of molasses included in cattle feed. During the mid 1990's a potentially serious, chronic syndrome was reported in well-managed beef and dairy herds from unrelated parts of South Africa. Farmers reported that it manifested as various combinations of seriously decreased production, increased reproductive disorders, apparent immune incompetence in previously immune competent animals, various mineral imbalances in non¬deficient areas and goitre, perceptible by enlarged thyroids. Farmers related this syndrome to certain batches of sugarcane molasses and molasses¬based products. Their opinion was based on observations that dramatic improvements in health and productivity often followed the withdrawal of the molasses component of the diet. The syndrome had all the characteristics of an "endocrine disruptive syndrome". Endocrine disrupting compounds (EDCs) are exogenous substances that have the potential to alter the functions of the endocrine system and consequently cause ill health. The EDCs comprise a diverse group of compounds that are widely used in detergents, in the paint and plastics industries and as wetting agents in agricultural remedies. Contamination of molasses with these compounds could occur as a result of uptake of chemicals by growing sugarcane or by the use of contaminated river water in the extraction of sugar from chopped sugarcane. It was essential to investigate the safety of molasses, currently available as stock feed in South Africa and the rest of the world, to allay any fears created by the farmers. Four batches of molasses previously collected from four different sugar mills located in different parts of the country were screened for potential endocrine disruptive activity, including oestrogen and thyroid activity and immune suppression. Two batches of molasses were selected to be used in a calf feeding trial. Thirty-two, 4 to 6 week-old Holstein bull calves of approximately the same weight, and supplied by the same rearing facility, were included in a single phase, three treatment, parallel design experiment. Calves from the three experimental groups were housed in the same facilities, under the same conditions and fed diets with similar composition. Two of the groups had molasses (Umzimkulu and Komatipoort) included in their rations and the control group was fed a ration where no molasses was added, but fermentable sugars and minerals were included. The weight gain of the calves was recorded over a six-month study period. Regular clinical examinations were conducted and clinical pathology parameters, immune responses and endocrine effects were evaluated. Even though endocrine disrupting effects were detected in in vitro screening tests, these could not be reproduced in calves under experimental conditions. The two batches of molasses utilized in the calf feeding trial did not induce major differences in any of the parameters measured, except a lower weight gain in the Umzimkulu molasses fed group which tended towards significance. It appears improbable that these two batches of molasses had any endocrine disruptive or immunosuppressive effects. Therefore, these two batches of molasses per se were not deleterious when fed to calves.Dissertation (MSc (Veterinary Sciences))--University of Pretoria, 2006.
Paraclinical Sciences
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Roy, Mélanie. "Identification and characterization of differentially expressed genes in response to Escherichia coli and Staphylococcus aureus in bovine mammary epithelial cells and mammary gland". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98785.
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Bovine mammary glands respond to infection by foreign pathogens such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) through changes in gene expression. Monitoring the gene expression profiles will contribute to better understanding of the pathology of mastitis, and provide important selective markers for future animal breeding programs. Using cultured bovine mammary duct epithelial cells and somatic cells from infected bovine mammary glands, this study first examined the existence of Toll Like Receptors in these two systems. In cultured duct epithelial cells stimulated with E. coli LPS, both TLR 4 and 2 mRNA up regulation was detected at 2h-72h and 12h-48h respectively. For S. aureus LTA TLR 2 mRNA was up regulated at 48 and 72h whereas for TLR 4 mRNA expression up regulation was detected at 24, 48, and 72h in comparison to the Oh (p<0.05). In the case of PGN, an abundant structural component of S. aureus, the expression of TLR 2 mRNA was significant (p<0.05) at 72h whereas TLR 4 mRNA expression increased at 24, 48, and 72h. The expression of these receptors was also monitored in milk cells from cows infected with either E. coli or S. aureus. However, results obtained from the milk cells were inconclusive due to the high individual variability. Afterwards, differential gene expression profiles were monitored by the Differential Display Polymerase Chain Reaction technique in the cultured duct epithelial cells in response to E. coli and S. aureus structural components. A total of 6 candidate fragments were identified for E. coli LPS induction, whereas only one fragment was identified for S. aureus LTA induction. After LTA induction, a specific band was found to be up regulated and confirmed to be GCP-2, a chemokine involved in neutrophil recruitment. In contrast, PGN induction resulted in no change in GCP-2 levels. In different preparations of cultured duct epithelial cells both GCP-2 and IL-8 were confirmed by real time PCR to be up regulated by LTA with a significance of (p<0.01) when compared to the control cells. In the case of the E. coli identified bands, a different approach is necessary to potentially confirm the origin of these fragments. Further large scale screening of the GCP-2 and IL-8 genes in dairy cattle is necessary to test for their potential use as targets to differentiate the mastitis resistant from the mastitis prone cows.
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Gould, Lowell. "Genetic variation of susceptibility to fescue toxicosis in cattle". Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-12232009-020514/.
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Illambas, Joanna. "Pharmacodynamic and pharmacokinetic-pharmacodynamic modelling of anti-microbial drugs in the treatment of calf pneumonia". Thesis, Royal Veterinary College (University of London), 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.669185.
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Abebe, Getachew. "The integrity of the hypothalamic-pituitary-adrenal axis in Boran (Bos indicus) cattle infected with Trypanosoma congolense". Thesis, Brunel University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292991.
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Chanlun, Aran. "Epidemiology of Neospora caninum infection in dairy cattle in Thailand /". Uppsala, Sweden : Dept. of Clinical Sciences, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200686.pdf.
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Byaruhanga, Charles. "Epidemiology and tick-borne haemoparasite diversity amongst transhumant Zebu cattle in Karamoja region, Uganda". Thesis, University of Pretoria, 2016. http://hdl.handle.net/2263/60141.
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This study was conducted to understand the occurrence, diversity and epidemiology of tickborne diseases (TBDs) in a transhumant pastoral area of Karamoja Region, Uganda. We used participatory epidemiology (PE), involving focus group discussions (n = 24) with livestock keepers, 30 key informant interviews, review of previous surveillance data, clinical examinations, and laboratory confirmation of cases of TBDs, to define and prioritise cattle diseases, evaluate current control activities, and identify constraints to the control of TBDs. The livestock keepers regarded TBDs, particularly East Coast fever (ECF) and anaplasmosis, as the most important health problems in their cattle, based on morbidity and mortality rates, rates of transmission, treatment costs, difficulty in accessing the correct treatment, difficulty to control, and inadequate knowledge to manage the diseases. The main constraints to the control of TBDs were inadequate knowledge, inadequate veterinary services and limited availability of drugs. Hand picking of ticks was done by all pastoralists while hand spraying was done with under-strength acaricides, often at irregular intervals and with little acaricide wash. We determined the endemic status of TBDs in 20 randomly-selected cattle herds by estimating the proportion of annual ECF and anaplasmosis cases in different age groups of cattle using participatory approaches and clinical examinations, determining the diversity and abundance of ticks (161 cattle in 20 herds), and establishing the seroprevalence of antibodies to Theileria parva and Anaplasma marginale among cattle (n = 397 in 20 herds). Clinical examinations and informant interviews showed that TBDs affected all age groups of cattle. Two-thirds of the cattle were infested with moderate (37.3%, 11-50 ticks) to abundant (28.6%, > 50 ticks) numbers of ticks. Out of the 10,923 ticks collected, Rhipicephalus appendiculatus (54.4%) was the most abundant species followed by R. decoloratus (17.7%), Amblyomma variegatum (12%) and A. lepidum (11.6%). We collected tick species that are either rare in Uganda (A. lepidum, Hyalomma truncatum, A. gemma) or were not known to be present in the country (R. pulchellus). The true seroprevalence of antibodies to A. marginale was high (95.1%, 95% confidence interval [CI] 91.3% - 98.5%), while that of T. parva was low (16.5%, 95% CI 12.9% - 19.6%). We determined the presence of tick-borne haemoparasites among cattle and the prevalence of infections using reverse line blot (RLB) hybridisation and quantitative real-time polymerase chain reaction (qPCR), and characterised Theileria and Babesia species by sequence and phylogenetic analyses of the full-length 18S rRNA gene. The RLB hybridisation assay demonstrated the presence of tick-borne haemoparasites in most cattle (99.6%), mostly as mixed infections (97.5%). The most frequently-detected species were Theileria mutans (88.3%, 95% CI: 84.6-92.1%), A. marginale (73.8%: 68.3-79.2%), T. velifera (71.3%: 65.8-76.7%) and Anaplasma sp. Omatjenne (63.3%: 57.5-68.8%). Other virulent pathogens, namely Babesia bigemina (5.0%) and T. parva (2.9%), were also detected with RLB, but Ehrlichia ruminantium was not detected. The proportions of qPCR positive samples were 82.9% (A. marginale), 12.1% (A. centrale), 3.3% (T. parva), and 1.7% (E. ruminantium). Variations (5 to 9 nucleotides) in the 18S rRNA gene sequences of B. bigemina were identified as compared with previously published sequences. We assessed the 16S rRNA gene phylogeny of Anaplasma species from cattle and analysed the msp1α gene sequences of A. marginale to identify genotypes. There was genetic heterogeneity within A. marginale in cattle in the study area. Most A. marginale sequences (16/19) were closely related (99- 100% identities) and clustered with A. marginale strain Veld from cattle in South Africa, with strong bootstrap support, while three sequences clustered (100% identity) with A. marginale strain from Virginia, USA. The A. centrale sequences were closely related (100% identity) and clustered with the Israel vaccine strain. We found four different kinds of MSP1a tandem repeat sequences (UP39-F-M2-3) that correspond to one A. marginale strain unique to Uganda. One tandem repeat (UP39) was unique to Karamoja cattle. The findings from this study provide knowledge on the diversity and epidemiology of TBDs, which can be used to support diagnosis and strategic control of TBDs, and consequently improve cattle productivity and the livelihoods of pastoralists. More effective control and prevention measures against ticks and TBDs should urgently be implemented in the region. There is need to facilitate and promote immunisation of cattle against ECF. Given the scarcity of veterinarians in the region, the activities of community-based animal health workers [CAHWs] should be strengthened. The local governments in Karamoja Region should facilitate a more favourable business environment to attract private companies, who could scale-up veterinary drug supplies to the region. Pastoralists should be sensitised to improve their ecological knowledge of the seasonal activity of ticks for strategic tick control.Thesis (PhD)--University of Pretoria, 2017.
Agricultural Technology and Agribusiness Advisory Services (ATAAS)
The National Agricultural Research Organisation (NARO) of Uganda
Veterinary Tropical Diseases
PhD
Unrestricted
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Thompson, Bronwen Eleanor. "Occurrence of Theileria parva infection in cattle on a farm in KwaZulu-Natal, South Africa". Diss., Electronic thesis, 2007. http://upetd.up.ac.za/thesis/available/etd-11012007-133653/.
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Behnke, Malgorzata Cecilia. "The role of behaviour and contact networks in the transmission of infectious diseases in dairy cattle". Thesis, University of Liverpool, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501707.
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Oial contact between a potential host and the infectious IS pathogen is essential for faecoorally transmitted diseases, of which there are several that affect dairy cattle. Variations in oral contact rates, durations and distributions can potentially alter the risk posed by Qch pathogens to the individual. Ihis thesis provides a comprehensive description of oral contact behaviours and relationships in dairy heifers and identifies management practices that may be modified to alter rates, durations and distribution of these behaviours. Spatial closeness networks were examined as potential measures of social affinity and to determine the relationship between spatial closeness and oral contact networks.
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Knight-Jones, Theo. "Field evaluation of foot-and-mouth disease vaccination in Turkey". Thesis, Royal Veterinary College (University of London), 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618321.
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Long, Ezhou. "Proliferation and apoptosis of bovine mammary epithelial cells : roles of eukaryotic translation initiation factor 4E and Escherichia coli mastitis". Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37766.
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Milk yield is dependent on both the number and secretory activity of mammary alveolar cells. The number of cells is controlled by their proliferation and death. In the first study, the effect of eukaryotic translation initiation factor 4E (eIF-4E) on the growth of a bovine mammary epithelial cell line, MAC-T, was investigated. Compared to the parental controls, overexpression of mouse wild-type (wt) eIF-4E in 11A, a subclone of MAC-T cells, increased the growth rate and saturation density (number of cells per well at confluence), whereas overexpression of a mutant eIF-4E (W56A) decreased growth rates and saturation densities. Furthermore, cyclin D1 expression among the 4E-overexpressing and parental cells was compared. Compared to the controls, the amounts of cyclin D1 mRNA and proteins were higher in the cells overexpressing wt eIF-4E but lower in the cells with mutant eIF-4E expression. Our results suggest that altered expression of eIF-4E leads to changes in cyclin D1 expression, which consequently modulate the growth properties of MAC-T 11A cells.Because of its unknown sequence, bovine eIF-4E cDNA was then cloned in the second study. Its coding region consists of 651 nucleotides which encode 217 amino acids (AAs). Bovine eIF-4E cDNA shares 94%, 89% and 94% homology with those of human, mouse and rabbit, respectively. Differences in protein sequences between bovine and human, mouse and rabbit eIF-4E are 2, 4, and 3 AAs, respectively. Furthermore, expression of eIF-4E in bovine mammary tissues at different physiological periods was investigated by Northern blot analysis, using the cloned cDNA as the probe. eIF-4E was not detectable at prepubertal period and expressed at a very low level at the third estrous cycle. In the lactating mammary tissues, eIF-4E was highly expressed. Differential expression of eIF-4E in bovine mammary gland at distinct physiological stages indicates its potential involvement in mammary development.
Cell proliferation and apoptosis were also studied in the Escherichia coli (E. coli)-infected bovine mammary glands in the last study. Both proliferation and apoptosis increased in the mastitic tissue, as determined by immunohistological assays. Compared to the controls, expression of the pro-apoptotic proteins, Bax and interleukin-1beta converting enzyme (ICE), increased at 24 h and 72 h post-infection, whereas expression of the anti-apoptotic protein Bcl-2 decreased only at 24 h post-infusion. Induction of extracellular matrix (ECM)-degrading enzymes, including matrix metal loproteinase-9 (MMP-9), stromelysin-1 (SL-1) and urokinase-type plasminogen activator (uPA), was also observed in the mastitic tissue. Therefore, apoptosis may be mediated through pathways involving the actions of Bcl-2, Bax and ICE, and may partially be accounted by ECM breakdown.
Taken together, our study has demonstrated the effect of eIF-4E on bovine mammary cell proliferation. In addition, its involvement in bovine mammary gland development has been suggested. Finally, increased mammary cell apoptosis and proliferation during E. coli-induced mastitis has been revealed, in association with altered expression of apoptosis-related genes and ECM-degrading enzymes. Understanding the regulation of mammary cell proliferation and death may eventually lead to improvement of milk production.
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Buczkowski, Hubert. "Development of marker vaccines for rinderpest (RPV) and peste des petits ruminants (PPRV) viruses". Thesis, Royal Veterinary College (University of London), 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558958.
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Bruce, Mieghan. "The impact of brucellosis in Albania : a systems approach". Thesis, Royal Veterinary College (University of London), 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701674.
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