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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The pathophysiology of Sarcocystis tenella infections in specific-pathogen-free (sporozoa) sheep / by Peter Harry Phillips.

Phillips, Peter Harry January 1982 (has links)
Some ill. mounted. / Bibliography: leaves [473]-504. / xxxvi, 505 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Pathology, 1984
22

A biochemical and immunological comparison of the Jaagsiekte and two related retroviruses.

York, Denis Francis. 25 September 2013 (has links)
Jaagsiekte is a contagious cancer affecting the lungs of sheep. Although the etiological agent is Jaagsiekte retrovirus (JSRV), two other retroviruses viz South African maedi visna virus ( SA - OMVV) and a novel Bovine retrovirus (BRV) have been associated with or implicated in the jaagsiekte disease complex. JSRV was sufficiently purified from lung rinse material using a Freon extraction, Percoll density gradient centrifugation and chranatography on a Sephacryl column, its polypeptide composition was studied by gel electrophoresis and its morphology observed electron microscopically. Monoclonal antibodies were made against purified preparations of the virus. Two hybridomas were isolated that produced MAbs which appear to be tumour cell specific. A third hybridoma, called 4A1O, produces antibodies considered to be viral specific. These MAbs have been used in the development of JS specific immunoassays. A cross reaction between JSRV and a polyclonal serum against Mason Pfizer monkey virus (MPMV) was confirmed and used in a Western blot technique to identify, monitor and differentiate JSRV from other viruses. During the study of JSRV it became apparent that another retrovirus was often present in JS infected lungs. This virus, referred to as SA - OM1V I, is a novel South African isolate of maedi visna virus (MVV). As SA - OM1V I has physicochemical characteristics similar to JSRV, it was often found in purified JSRV preparations. Being a retrovirus it is also detected by the reverse transcriptase assay which was the only method used to assay and monitor for JSRV during the early stages of our work. Using a Westen blot technique and sera against MVV and MPMV it was possible to simultaneously detect and differentiate JSRV from SA - OMVV I. A method was also developed whereby the two viruses could be separated from each other during purification. The information gained and techniques developed whilst studyiing JSRV were also used to isolate and characterize BRV. This novel virus originated from bovine cells that had been co-cultivated with white blood cells from an ox suffering from malignant catarrhal fever. Three out of four sheep inoculated with BRV developed JS. It therefore had to be· ascertained whether this virus was related to JSRV or not. The comparative study revealed that BRV was biochemically and morphologically quite different fran JSRV. Interestingly, it was shown that serum against MPMV cross reacted with a 32 kd protein of BRV indicating a serological relationship between JSRV, MPMV and BRV. The possible role of BRV in the etiology of jaagsiekte remains to be elucidated. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1987.
23

Investigating novel aspects of FMDV pathogenesis in pregnant ovines, foetuses and neonatal lambs

Waters, Ryan Andrew January 2012 (has links)
No description available.
24

Contagious ecthyma virus infection of sheep: virologic and immunologic investigations

Buddle, Bryce Malcolm January 1981 (has links)
Ph. D.
25

Effect of monensin supplementation on ruminal and postruminal digestion in sheep and on adaptation of ruminal microbes

Rogers, Michaela G. January 1987 (has links)
Three experiments were conducted to examine the effects of an ionophore, monensin sodium, on digestion in sheep. The first experiment was concerning alterations induced by long-term supplementation and subsequent withdrawal of the ionophore. The diet was a pelleted mixture of 43% native prairie hay, 34% corn grain, and 21% lupin grain plus 100 g wheat straw. Monensin (33 ppm) was added to the diet of four wethers, and four other animals served as controls and consumed an identical diet. without monensin. Monensin supplementation increased (P <.05) ruminal propionate while decreasing (P <.05) acetate levels throughout the 146-d experiment. Withdrawal caused acetate to return to control levels but decreased (P <.05) propionate. During ionophore supplementation, the digestibilities of organic matter (OM) and dry matter (DM) were increased (P <.05) by an average of 8 and 9%, respectively. Apparent digestibility ' of N was increased from 75 to 77% after 19 d of supplementation. There was an augmentation (P <.05) in the flow of bacterial N at the duodenum after 96 d of supplementation. This effect disappeared with ionophore withdrawal. In a second experiment, the effect of monensin on postruminal digestion was examined in three trials with six wethers. There were three treatments: control, dietary monensin, and monensin infused into the duodenum. The diets were the same as in the previous experiment. Dietary monensin caused the same changes in ruminal VFA as in the previous experiment. Infused monensin had no effect on VFA. Dietary monensin increased (P <.05) trypsin activity at the ileum. Dietary ionophore did not alter nutrient digestibilities, but shifted (P <.O5) the site of OM and DM digestion from the cecum to before the terminal ileum by 14 and 10%, respectively. In an in vitro experiment rumen contents from monensin-adapted and nonadapted sheep were compared with and without additional ionophore in a 6 h incubation system. Rumen contents from adapted sheep did not differ from contents of nonadapted sheep in the quantity of microbial N synthesized. With monensin addition to the incubation, microbial synthesis dropped by 49% in nonadapted microorganisms. In adapted contents, the decrease in synthesis was only 9%. Monensin-adapted microbes degraded (P <.O1) more protein substrate than those which were not adapted. / Ph. D. / incomplete_metadata
26

Ruminant brucellosis in Egypt : frequency, distribution and potential control strategies

Hegazy, Yamen Mohammed January 2010 (has links)
No description available.
27

Correlation of endophyte toxins (ergovaline and lolitrem B) with clinical disease : fescue foot and perennial ryegrass staggers

Tor-Agbidye, John 13 August 1993 (has links)
Endophytic fungi (A. coenophialum and A. lolii) which infect grasses produce ergot alkaloids that serve as the grasses' chemical defenses and enhance the vigor of the grass. Turf-type tall fescue with high endophyte levels has been deliberately developed to produce a greener, more vigorous, pest-resistant turf. Consumption of endophyte-infected grass causes various toxicity symptoms in livestock. Cattle in the southeastern and midwestern United States, where tall fescue is grown on 14 million hectares, often develop signs of toxicosis during summer months from grazing plants in fected by A. coenophialum. A more severe form of the disease, fescue foot, has been associated with cold environment and reported in late fall and winter months not only in the southeastern United States but also in the northwest United States. In New Zealand, where perennial ryegrass is grown on 7 million hectares of pasture, sheep often develop a condition called ryegrass staggers from grazing plants infected by A. lolii. New Zealand reports economic losses grazing plants infected by A. lolii. New Zealand reports economic losses associated with the sheep industry of $205 million per year. In the United States, economic losses associated with the beef cattle industry alone is estimated at $600 million per year. Range finding experiments and case studies of fescue foot and perennial ryegrass staggers (PRGS) were conducted on cattle and sheep under grazing and barn conditions. The main objective was to determine threshold levels of the endophyte toxins, ergovaline (EV) (appendix 1) and lolitrem B (appendix 2), associated with the diseases of fescue foot and PRGS respectively. Fescue foot was experimentally induced in cattle under barn studies in the spring with 825 ppb ergovaline. The ergovaline contaminated feed was given for a period of 42 days. Similar barn studies in sheep in spring to early summer did not produce clinical fescue foot with up to 1215 ppb. Field studies of natural fescue foot in a herd of sheep were conducted, (ie 540 ppb) values of ergovaline in the feed, but clinical disease was not produced in late fall through winter. A case study from a herd of sheep revealed 813 ppb dietary ergovaline had produced fescue foot in the months of fall (November). Fields of perennial ryegrass (PRG) where sheep received 2,135 ppb lolitrem B toxin were associated with clinical cases of PRGS in 42 sheep of 237 sheep (18 percent incidence rate) in the Willamette Valley of Oregon. Three months later, sheep on this same field which then had 1,465 ppb lolitrem B, did not have PRGS. These were the first range finding experiments undertaken in this locale to document threshold levels of endophyte toxins associated with fescue foot and PRGS. / Graduation date: 1994
28

Toxoplasma gondii infection in sheep : studies on epidemiology, food hygiene and vaccination /

Lundén, Anna, January 1900 (has links)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.
29

Comparação de técnicas no diagnóstico da infecção leptospírica em ovinos e implicações na saúde pública /

Fornazari, Felipe. January 2012 (has links)
Orientador: Helio Langoni / Banca: Jane Megid / Banca: Márcia Marinho / Resumo: A leptospirose é uma enfermidade infecto-contagiosa, de caráter zoonótico, que possui grande importância mundial. É causada por diversas espécies de bactérias patogênicas do gênero Leptospira, ocorrendo com maior frequência em regiões tropicais com condições sanitárias precárias. A infecção ocorre pelo contato direto ou indireto com a urina de animais infectados, e pode variar de assintomática até quadros clínicos graves que causam a morte. A leptospirose em ovinos é responsável por queda na produção animal, e por riscos para a saúde pública. O desenvolvimento de técnicas de diagnóstico permite identificar animais doentes, auxiliando no tratamento precoce, controle de reservatórios, e na prevenção da enfermidade. O presente estudo teve como objetivo principal comparar diferentes técnicas de diagnóstico na leptospirose em ovinos. Amostras de rim, fígado e sangue foram coletadas de 465 animais provenientes de um abatedouro. O soro foi submetido à Soroaglutinação Microscópica (SAM), e as amostras de rim e fígado dos animais soropositivos foram individualmente analisadas por quatro técnicas: cultivo bacteriano, técnica de Warthin Starry (WS), PCR convencional (PCR) e PCR quantitativa (qPCR). Amostras teciduais de 15 ovinos soronegativos, escolhidos aleatoriamente, foram utilizadas como controles negativos. No exame sorológico 21 animais foram positivos (4,5%) para os sorovares Hardjo (n=12), Hebdomadis (n=5), Sentot (n=2), Wolfii (n=1) e Shermani (n=1). Os títulos apresentados foram 100 (n=10), 200 (n=2), 400 (n=6) e 1600 (n=3). No cultivo bacteriano nenhum animal apresentou resultado positivo; na técnica de WS quatro animais foram positivos em amostras de rim, e nenhum de fígado; na PCR seis animais foram positivos em amostras de rim, e nenhum de fígado; e na qPCR 11 animais foram positivos, 8 em amostras... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Leptospirosis is an infectious disease, of zoonotic character, which has great importance worldwide. It is caused by several species of pathogenic bacteria of Leptospira genera, occurring more frequently in tropical regions with poor sanitary conditions. The infection occurs by direct or indirect contact with urine of infected animals, and can vary from asymptomatic to severe clinical pictures that lead to death. Leptospirosis in sheep is responsible for decrease in animal production, and for risks in public health. The development of diagnostic techniques allows to identifying sick animals, assisting in early treatment, reservoirs control, and disease prevention. The present study had as main objective to compare different techniques of leptospirosis diagnostic in sheep. Samples of kidney, liver and blood were collected from 465 animals originated from a slaughterhouse. The sera were submitted to Microscopic Agglutination Test (MAT), and kidney and liver samples of seropositive animals were individually analyzed by four techniques: bacteriological culture, Warthin Starry (WS) technique, conventional PCR (PCR), and quantitative PCR (qPCR). Tissue samples from 15 seronegative sheep, chosen randomly, were used as negative controls. In serologic exam 21 animals were positive (4.5%) to serovars Hardjo (n=12), Hebdomadis (n=5), Sentot (n=2), Wolfii (n=1) and Shermani (n=1). The titers presented were 100 (n=10), 200 (n=2), 400 (n=6) and 1600 (n=3). In bacteriologic culture no animal presented positive result; in WS technique four animals were positive in kidney samples, and none in liver; in PCR six animals were positive in kidney samples, and none in liver; and in qPCR 11 animals were positive, 8 in kidney samples and three in liver samples. The bacterial quantification resulting from qPCR revealed median of 4.32 bacteria/μL in liver... (Complete abstract click electronic access below) / Mestre
30

Comparação de técnicas no diagnóstico da infecção leptospírica em ovinos e implicações na saúde pública

Fornazari, Felipe [UNESP] 27 February 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-27Bitstream added on 2014-06-13T20:59:41Z : No. of bitstreams: 1 fornazari_f_me_botfmvz.pdf: 2852612 bytes, checksum: e40a8e5e7c4376ca3afa50ffbb940c4c (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A leptospirose é uma enfermidade infecto-contagiosa, de caráter zoonótico, que possui grande importância mundial. É causada por diversas espécies de bactérias patogênicas do gênero Leptospira, ocorrendo com maior frequência em regiões tropicais com condições sanitárias precárias. A infecção ocorre pelo contato direto ou indireto com a urina de animais infectados, e pode variar de assintomática até quadros clínicos graves que causam a morte. A leptospirose em ovinos é responsável por queda na produção animal, e por riscos para a saúde pública. O desenvolvimento de técnicas de diagnóstico permite identificar animais doentes, auxiliando no tratamento precoce, controle de reservatórios, e na prevenção da enfermidade. O presente estudo teve como objetivo principal comparar diferentes técnicas de diagnóstico na leptospirose em ovinos. Amostras de rim, fígado e sangue foram coletadas de 465 animais provenientes de um abatedouro. O soro foi submetido à Soroaglutinação Microscópica (SAM), e as amostras de rim e fígado dos animais soropositivos foram individualmente analisadas por quatro técnicas: cultivo bacteriano, técnica de Warthin Starry (WS), PCR convencional (PCR) e PCR quantitativa (qPCR). Amostras teciduais de 15 ovinos soronegativos, escolhidos aleatoriamente, foram utilizadas como controles negativos. No exame sorológico 21 animais foram positivos (4,5%) para os sorovares Hardjo (n=12), Hebdomadis (n=5), Sentot (n=2), Wolfii (n=1) e Shermani (n=1). Os títulos apresentados foram 100 (n=10), 200 (n=2), 400 (n=6) e 1600 (n=3). No cultivo bacteriano nenhum animal apresentou resultado positivo; na técnica de WS quatro animais foram positivos em amostras de rim, e nenhum de fígado; na PCR seis animais foram positivos em amostras de rim, e nenhum de fígado; e na qPCR 11 animais foram positivos, 8 em amostras... / Leptospirosis is an infectious disease, of zoonotic character, which has great importance worldwide. It is caused by several species of pathogenic bacteria of Leptospira genera, occurring more frequently in tropical regions with poor sanitary conditions. The infection occurs by direct or indirect contact with urine of infected animals, and can vary from asymptomatic to severe clinical pictures that lead to death. Leptospirosis in sheep is responsible for decrease in animal production, and for risks in public health. The development of diagnostic techniques allows to identifying sick animals, assisting in early treatment, reservoirs control, and disease prevention. The present study had as main objective to compare different techniques of leptospirosis diagnostic in sheep. Samples of kidney, liver and blood were collected from 465 animals originated from a slaughterhouse. The sera were submitted to Microscopic Agglutination Test (MAT), and kidney and liver samples of seropositive animals were individually analyzed by four techniques: bacteriological culture, Warthin Starry (WS) technique, conventional PCR (PCR), and quantitative PCR (qPCR). Tissue samples from 15 seronegative sheep, chosen randomly, were used as negative controls. In serologic exam 21 animals were positive (4.5%) to serovars Hardjo (n=12), Hebdomadis (n=5), Sentot (n=2), Wolfii (n=1) and Shermani (n=1). The titers presented were 100 (n=10), 200 (n=2), 400 (n=6) and 1600 (n=3). In bacteriologic culture no animal presented positive result; in WS technique four animals were positive in kidney samples, and none in liver; in PCR six animals were positive in kidney samples, and none in liver; and in qPCR 11 animals were positive, 8 in kidney samples and three in liver samples. The bacterial quantification resulting from qPCR revealed median of 4.32 bacteria/μL in liver... (Complete abstract click electronic access below)

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