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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.
101

Testing the effectiveness and cost-efficiency of livestock guarding dogs in Botswana

Horgan, Jane Elizabeth January 2016 (has links)
Livestock guarding dogs (LSGDs) have been used for centuries to reduce depredation on livestock and more recently, to facilitate the conservation of threatened predator species. Conservation NGOs (non-government organisations) in southern Africa promote the use of Anatolian Shepherds as LSGDs. However, livestock farmers in Botswana have been using a variety of different breeds for this purpose, including the local mixed-breed “Tswana” dogs. Postal, telephonic and face-to-face interview questionnaires were administered to 108 livestock farmers in Botswana to gauge how their LSGDs were being used, in order to determine what factors contributed to the success and affordability of these dogs. Eighty-three percent of farmers had LSGDs which equaled or decreased livestock depredations on their farms, with an average reduction in livestock depredation of 75 percent per year. This equated to an average saving of US$2,017 annually per farm. The costs of purchasing (average US$27) and maintaining the 198 LSGDs in my study (average US$169/LSGD/year) were very low compared to other countries and helped contribute to the high profits obtained by farmers (average US$1,497/farm or US$789/LSGD). A unique investigation of different breeds was possible due to the diverse array of breeds in the sample (Anatolian Shepherds, Cross Breeds, Tswana dogs, Greyhounds and Pitbulls), with the crossbreed dogs (Crosses and Tswana LSGDs) performing the best. LSGDs that reduced depredation and had minimal behavioural problems were the most likely to incite positive changes in their owners in regards to attitudes towards predators. Sixty six percent of farmers stated that they were more tolerant of predators since obtaining a LSGD, and 51 percent reported that they were less likely to kill predators since obtaining a LSGD. My results indicate that successful, well-behaved LSGDs are a cost-effective tool that has the ability to increase farm productivity and improve predator-farmer conflicts in Botswana. The methods recommended in my thesis, in particular the benefits of using local breeds of dog as LSGDs, can be implemented on farming practices the world over to assist farming productivity and to promote conservation efforts.
102

Characterizing native palatable legume and non-legume species in the rangelands of the Overberg area

Gallant, Luke Howard January 2020 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / The Overberg renosterveld rangelands of the Cape Floristic Region (CFR) has become well associated with commercial and communal agricultural practices, namely crop and livestock production. This Mediterranean region is characterized as being a semi-arid, winter rainfall area with nutrient-limited soils. Livestock farmers rely largely on introduced legume species such as lucerne (Medicago sativa) as high quality forage to sustain their livestock’s diets. Generally, these introduced species are reliant on the accessibility of water and nutrients, due to the specific climatic and edaphic conditions of the region. The availability of high quality forage has always been a major concern to farmers when it comes to managing their livestock, since livestock productivity is determined by the quality of the forage consumed.
103

An Interregional Study of Kenya's Livestock Sector Using Linear Programming

Mwangi, Zakayo Joseph 01 May 1981 (has links)
The major purpose of this study was to determine the least- cost method of producing red meat in Kenya. Linear programming was used in the study. A simulated reduction of grazing land available in one of the settlement areas was carried out to indicate what effect this had on the overall regional production pattern of meat in the country. Kenya was divided into eleven livestock producing and consuming regions. 1979 was used as the base year, and the demand projection was based on the 1979 population. Input and output coefficients, livestock unit requirements, and market prices were developed. A linear programming model was then used to generate the optimal production and marketing of both cattle and small stock .
104

An epidemiological study of foot and limb lesions in growing pigs

Mouttotou, Niki January 1998 (has links)
No description available.
105

A study of relationships between fat partition and metabolism in Hereford and Friesian steers

Truscott, Terry Gordon January 1980 (has links)
No description available.
106

Ecological economics of wildlife disease control

Cox, Mark January 1999 (has links)
No description available.
107

The nutritive value of alkali-treated straws as assessed by chemical methods of analysis and by the near infrared spectroscopy technique

Zamime, Benaceur January 1995 (has links)
No description available.
108

Host-virus interactions in porcine reproductive and respiratory syndrome virus infection

Sorensen, George Edwin Peter January 2014 (has links)
Porcine reproductive and respiratory syndrome virus (PRRSV) is a rapidly evolving virus that has significant economic and welfare implications for the pig industry. Vaccination strategies have proved largely ineffective in controlling PRRSV, in some cases even reverting to virulence. An increasing body of evidence suggests a host genetic basis for PRRSV resistance so there is a need to examine the role of host genetics in a biologically relevant in vitro cell culture system. However, PRRSV research is inhibited by the current scarcity of suitable in vitro culture systems. With the aim of developing a convenient in vitro model, porcine bone marrow-derived macrophages (BMDM) were evaluated as a PRRSV cell culture system. BMDM were found to be highly permissive to Type I PRRSV and amenable to genetic manipulation. BMDM proved to be excellent cells for virus production, producing significantly higher titres of PRRSV than commonly used alternative cell types. Surprisingly, PRRSV entry into BMDM was found to be independent of both the prototypic PRRSV receptors, CD163 and CD169, providing further evidence for the existence of alternate PRRSV entry mechanisms in primary cell types. To explore the genetics of pig susceptibility to PRRSV, network-based analysis of host transcriptional datasets, following PRRSV challenge, revealed important differences in co-regulated gene pathways between samples from pigs with different PRRSV-permissiveness. These pathways included genes with important, recently characterised, anti-pathogen activities. The incorporation of network-based transcriptional analysis and published genetic variation data led to the identification of a member of the guanlyate binding protein family, GBP-1, as a candidate host gene involved in controlling PRRSV replication. Overexpression of GBP-1 in BMDM revealed a significant anti-PRRSV function for this protein. Further investigation of published genetic variation in GBP-1 suggested a potential role of this gene in PRRSV tolerance. The results presented in this thesis provide evidence for an alternate PRRSV entry pathway in a biologically relevant cell type. The discovery of a highly PRRSV-infectable cell type with potential for genetic manipulation adds a useful new tool to the area of PRRSV research. The identification of GBP-1 as a novel anti-viral protein with a significant inhibitory effect on PRRSV infection, together with genetic variation in this gene, prompts further research into the genetic basis for PRRSV resistance.
109

An Analysis of Junior Livestock Shows in Utah

Bingham, Mark Jay 01 May 1975 (has links)
The purpose of this paper is to discover any trend developing in youth participation in junior livestock shows in Utah and to identify the factors which affect youth participation. Junior livestock show records and 4-H enrollment figures from Cache and Box Elder Counties and the State of Utah, were studied to obtain necessary statistical information. A survey was constructed and issued to former and present 4-H members. Economic theory was employed in order to compare the survey data and participation statistics. The paper is divided into three major parts: similarities and differences between the Cache and Box Elder County Fair Junior Livestock Shows, age group comparisons, and other comparisons, in that order.
110

Epidemiology of infection with leptospira species in livestock in Papua New Guinea

nvetlab@online.net.pg, Peter Meiwan Wai'in January 2007 (has links)
The role of infection with Leptospira as a cause of infertility in Papua New Guinea(PNG) has not been confirmed, mainly because of the lack of robust and simple diagnostic tests in PNG. The aims of this study were to determine the seroprevalence and distribution of infection in livestock in PNG and to develop and validate a diagnostic test for use in PNG that was sufficiently accurate and reliable for confident interpretation of the results. The nested and real-time PCRs were assessed for use as diagnostic tools. The first survey was conducted on 3 commercial, 3 smallholder cattle farms and 4 abattoirs in March 2004 in PNG. Each herd was stratified into 3 age groups (< 2, 2-5 and >5 years), and sera from 1379 animals were sampled in Lae and Kimbe. In addition, 73 kidneys were collected from cattle at the abattoir and aseptically processed for culture. Two hundred and eighty three sera were collected from pigs killed at the abattoirs and 79 pig kidneys were collected and cultured. All sera were tested using the microscopic agglutination test (MAT). The dominant serovar infecting the cattle in PNG was Hardjo with a seroprevalence of 53.7%. The prevalence of serovar Hardjo in the six farms and the abattoir was significantly higher than serovars Tarassovi and Pomona (P < 0.05). All pig sera were negative for Leptospira. Leptospires were isolated by culture and the isolates were typed and identified as L. borgpetersenii serovar Hardjo. Cattle are a recognized reservoir for serovar Hardjo and may have a role in transmission to humans. The second survey was conducted in June 2006 to determine if cattle from smallholder farmers, village pigs and dogs in the Markham Valley in Lae, PNG were infected with Leptospira. In addition, pigs from a commercial piggery and horses from commercial and smallholder farms were also sampled. A total of 69 pig sera, 22 dog sera, 15 horse sera and 111 cattle sera were collected. The results showed that 1 dog and 1 pig were seropositive with serovar Canicola. Of the 111 cattle sampled, 21 were seropositive for Hardjo. It was concluded that the seroprevalence with serovar Hardjo in these cattle was significantly lower than cattle from commercial properties. Smallholder cattle may therefore not be a major source of Hardjo infection for animals on commercial farms and pigs do not appear to be infected with Leptospira. The Ab-ELISAs were constructed using one crude preparations of L. interrogans serovar Pomona and 2 different crude preparation of L. biflexa serovar Patoc. The three antigen preparations were evaluated using 21 MAT-positive and 96 MAT-negative pig sera to determine which antigen preparation was suitable for use in an Ab–ELISA. The selected antigen preparation (L1) was validated in the test using serum from 2 cattle and 1 pig population that were seropositive for Leptospira. A sub-population of seronegative cattle and pigs were also used. The Ab-ELISA was used to test 1,465 bovine sera from 8 cattle populations and the results were compared with the MAT using a Bayesian framework, to obtain an unbiased estimate of the accuracy of the tests. The ELISA had high sensitivity and specificity. Results from the Bayesian analysis showed that the sensitivity and specificity estimates for the Ab-ELISA were high compared to the MAT. Based on the test accuracy and its performance the Ab-ELISA using the L1 antigen described in this study is suitable for use in countries like PNG where the MAT is difficult to perform. Samples of kidneys from livestock in PNG were tested using culture and a PCR-based assay to detect Leptospira species. A total of 72 samples of kidney were collected from cattle and a total of 74 samples were collected from pigs slaughtered in Lae and Port Moresby. A second study was designed to assess the use of a real-time PCR for detecting leptospiral DNA in urine from cattle. One hundred and ninety-three urine samples were collected from a beef cattle farm in WA. Whole genomic DNA from kidney samples was extracted from each kidney using the QIAamp DNA Mini kit (Qiagen). Heat lysis was used to extract genomic DNA from clear urine samples and the QIAamp Mini Kit was used for urine that was contaminated with faeces. The PCR-based test was able to detect a higher number of Leptospira-positive kidneys compared to culture in EMJH medium. Results of testing DNA extracted from urine using the realtime PCR showed that this test is sensitive and able to detect cattle infected with pathogenic leptospires.

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