Tesis sobre el tema "Livestock"

Accounting for livestock activities affords particular accounting questions pertaining to asset valuation and profit measurement. The livestock industry impacts significantly on the Australian economy, but accounting information produced by firms in the industry has escaped accounting regulation. Traditional accounting theory suggests that uniformity in reporting provides optimal information for users of accounting reports and that lack of appropriate regulation results in diversity in reporting practices. Livestock represents one category of self-generating and regenerative assets [SGARA] and the purpose of this thesis is to develop recommendations on livestock accounting practices to assist in developing an accounting standard for SGARA generally. In achieving this aim, the thesis considers existing guidelines developed by professional bodies in other countries, professional recommendations and research papers produced in Australia and current Australian practice as revealed by the published accounting reports of Australian Companies. Despite the small sample available, published reports show marked differences in accounting policies and in the level of disclosure. Classes of livestock held, and the purposes of holding livestock vary. Most firms in the Australian livestock industry are not reporting entities. The more uncommon forms oflivestock tend to be held by non-reporting entities. Accordingly, accounting recommendations concentrate on traditional categories such as sheep and cattle. The major recommendation is the valuation oflivestock at net market value. Changes in value influenced by entity management are reflected in profit or loss for the period. Unrealised changes in value resulting from movements in market prices are transferred to a livestock revaluation reserve.

Although diarrhoea caused by Cryptosporidium is prevalent in livestock species throughout the world relatively little is known about the species and subtypes of Cryptosporidium found in cattle on Scottish farms. In particular, little is known about the shedding profiles (age when calves become infected and duration of shedding) of the different species found in cattle and how calves become infected. There are several theories about how neonatal calves first become infected with the parasite but the role which adult cattle play in the transmission of the parasite has not been fully addressed. It was previously thought that adult cattle did not become infected with the same species of Cryptosporidium which causes disease in the young calves. Some studies have shown that this may not be true and with the advance of new techniques to discriminate species this is an area which should be revisited. In addition, it is known that it is possible for humans to become infected with Cryptosporidium and show clinical disease early in life and then again later in adulthood. In livestock however, diarrhoea caused by the parasite is generally only seen in neonatal livestock while older animals tend to be asymptomatic. It is not known if this resistance to clinical disease at an older age is due to changes in the host with an increase in age or if prior infection “immunises” the animal and provides protection against re-infection. It is also not known if infection with one isolate of C. parvum will provide protection against infection with another or if the protection formed is species/isolate specific. The main aims of this thesis were to: determine the species and subtypes of Cryptosporidium found in calves on a study farm over a one year period from birth; assess the role which adult cattle play in the transmission of the parasite to newborn calves; develop new typing tools to enable the rapid and easy differentiation of Cryptosporidium species found in cattle and to examine the host-pathogen interactions in animals given serial experimental challenges with distinct Cryptosporidium parvum isolates to determine if the resistance seen in older animals on farms is due to an increase in age or as a result of prior infection. iii A variety of different approaches were taken to achieve these aims. Longitudinal experiments carried out on a study farm revealed that in calves < 9 weeks of age the most common species of Cryptosporidium is C. parvum and that all calves in the group became infected with Cryptosporidium within the first two weeks of life. Sample collection from the same animals later in life (at 6 months of age) showed that contrary to most previous studies the most common species detected at in this age group was also C. parvum although, interestingly, the subtype which the calves were shedding was not the same subtype that they were shedding previously. The longitudinal study which investigated the role of adult cattle in the transmission of Cryptosporidium also yielded some interesting results. It was found that most of the adult cattle on this farm were shedding Cryptosporidium albeit intermittently. Speciation of the positive samples revealed that, on this farm, the most predominant species of Cryptosporidium in adult cattle was also C. parvum. This is very unusual as most previous studies have not found this level of infection in older cattle and C. parvum is not usually found in this age group. A number of different subtypes were found in adult cattle and some animals shed more than one subtype over the course of the study. This contradicts prior findings which demonstrated that only one subtype is found on a single farm. The experimental infection trial involving infection of young (<1 week old) and older (6 week old) lambs with distinct C. parvum isolates demonstrated that an increase in age at primary infection reduces the effect of clinical disease. Animals which were infected at <1 week of age were re-challenged at 6 weeks of age with either a homologous or heterologous infection. Results revealed that previous exposure does not protect against re-infection with the same or a different isolate of C. parvum. This study also demonstrated that an increase in infective dose leads to a shorter pre-patent period and that there are variations in the clinical manifestations of different isolates of the same Cryptosporidium species.

The use of livestock guarding dogs (LGDs) to mitigate farmer-predator conflict in Namibia was evaluated. As farmer-predator conflict has two sides, LGDs were evaluated in terms of livestock production and conservation. The main objectives in terms of livestock production were to document: 1) the perceived ability of LGDs to reduce livestock losses in a cost-effective manner; 2) the farmers’ satisfaction with LGD performance; and 3) factors influencing LGD behaviour. The main objectives in terms of conservation were to record: 1) predator killing by farmers relative to LGD introduction; 2) direct impacts of LGDs on target (damage-causing) species; and 3) the impact of LGDs on non-target species. This evaluation was conducted on LGDs bred by the Cheetah Conservation Fund (CCF) and placed on farms in Namibia. The data were collected during face-to-face interviews with farmers using LGDs. Historical data from the CCF programme were used in conjunction with a complete survey of the farmers in the CCF LGD programme during 2009-2010. In terms of livestock production, 91 percent of the LGDs (n = 65) eliminated or reduced livestock losses. Subsequently, 73 percent of the farmers perceived their LGDs as economically beneficial, although a cost-benefit analysis showed that only 59 percent of the LGDs were cost-effective. Farmers were generally satisfied with the performance of their LGDs. However, farmer satisfaction was more closely linked to good LGD behaviour than the perceived reduction in livestock losses. The most commonly-reported LGD behavioural problems (n = 195) were staying at home rather than accompanying the livestock (21 percent) and chasing wildlife (19 percent). LGD staying home behaviour was linked to a lack of care on subsistence farms, as high quality dog food was not consistently provided. Care for LGDs declined with LGD age on subsistence, but not commercial, farms. In terms of conservation, predator-killing farmers killed fewer individuals in the year since LGD introduction than previously; this result was only significant for black-backed jackal Canis mesomelas. However, 37 LGDs killed jackals, nine killed baboons Papio ursinus, three killed caracals Caracal caracal and one killed a cheetah Acinonyx jubatus (n = 83). Farmers and LGDs combined killed significantly more jackals in the survey year than the same farmers (n = 36) killed before LGD introduction. Conversely, five farmers killed 3.2 ± 2.01 cheetahs each in the year before LGD introduction, whereas LGDs and these farmers combined killed only 0.2 ± 0.2 cheetahs per farm in the survey year. Only 16 LGDs (n = 83) killed non-target species. The high LGD success rate in terms of livestock production was facilitated by livestock husbandry practices in the study area. In terms of conservation, LGDs were more beneficial for apex predators than for mesopredators and had a minor impact on non-target species.

Thesis (Honors)--Ohio State University, 2007.<br>Title from first page of PDF file. Document formatted into pages: contains 43 p.; also includes graphics. Includes bibliographical references (p. 30-32). Available online via Ohio State University's Knowledge Bank.

In response to sustainable land management requirements and catchment-scale hydrological modelling needs, scientific interest in hydrological'connec~ivity'hasgrown. However, little is ~ . known about how hydrological connectivity is impacted by management. While there has been much research into livestock grazing and soil erosion in the UK; relatively little research has been conducted to characterize the hydrological patterns of livestock impacts, especially in organic soils which might be more vulnerable to environmental degradation. This thesis examines livestock impacts, as a land use case study, to conceptualize the 'dynamic nature of hydrological connectivity and its potential changes on hillslope and catchment hydrology. Different grazing strategies on organic soils (blanket p~ats and peaty gleys) in the uplands of Upper Wharfedale and Teesdale and organo-mineral soils (stagnogleys) in lowlands at Kirkby Overblow, northern England are investigated. Field measurements and monitoriIig are combined with laboratory experiments and proces~-based distributed modelling. Results suggest that compaction effects from sheep differ between soil types and topographic context but that they were generally confined to the upper 20 cm of the soil profile but with greater impacts in the upper 5 cm. Light-medium grazing (-9 a ha-1 ) significantly raised mean bulk density compared to adjacent soils with no grazing in the upper 10 cm of the soil profile of'stagnogleys. The relatively heavy grazing associated with frequently trampled areas under sheep tracks on stagnogleys was associated with soils with a mean bulk density 10 % greater (in the upper 10 cm of the soil) than those in the surrounding lightly grazed soil for stagnogleys, 2 % in 0-5 cm arid 9 % in 5-10 cm layers of peaty gleys, and at least 50 % in the near surface of peats. The effects of sheep tracks on soil properties and hydrological function were found to extend by at least 2 m further either side ofthe track rather than just being a feature ofthe visible track alone. Removing sheep led to a substantial fall in compaction effects in peats (10.4-21.7 % in bulk ~ensity) and stagnogley soils (0.5 % in bulk density) within a short time period (4-6 years). There were also significant differences in jnfiltration rates between short-term exclosure sites ' and grazed sites. For peat soils differences between lightly graZed areas and the long-term ' exclosures (35-45 years) were not much greater than those between the lightly grazed areas and the short-term exclosures suggesting that soil response to removal of sheep can be rapid. This thesis demonstrated that both the value and actual spatial distribution of livestock may .significantly decrease vertical connectivity and increase lateral connectivity, and hence increase both the spatial and temporal frequency of overland flow. In the organic soils of the humid-temperate zone studied this is through alteration of saturation-excess processes rather than infiltration-excess flow generation; antecedenfwater stores or soil moisture content are therefore of great, importance in hydrological connectivity responses to livestock impacts. Sheep tracks can be crucial in producing more rapid and connected overland flow on peats and stagnogleys, and effects extend several metres ether side of the track. Blanket peats are more vulnerable to livestock grazing than stagnogleys. The modelling approach used on stagnogleys from Kirkby Overblow suggests that increasing sheep density in very wet environments would lead to enhanced flood risks in terms of overall runoff amount and more rapid response due to e$anced coupling of hillslope arid river corridors, especially in extreme rainfall conditions.

A cell based system for the production of transgenic animals would offer significant advantages, allowing in vitro analysis of transgenes before the production of whole animals, precise placement of transgenes and the possibility of deletion, replacement or mutation of endogenous genes. In mice embryonic stem cells provide a tool for such precise genetic manipulation. However, despite considerable efforts, neither ES nor EG cells capable of contributing to the germline of any livestock species have been isolated. This dissertation describes cell mediated transgenesis by in vitro transfection of cultured cells followed by nuclear transfer. Several different cell cultures were assessed for their suitability for nuclear transfer. Viable lambs were obtained from embryonic, fetal and adult somatic cells. This demonstrated for the first time that cellular totipotency is not irreversibly lost during differentiation. Some but not all of these cell types could support cell mediated transgenesis. A genomic Factor IX construct designed to express in the lactating mammary gland has been generated and used to demonstrate nuclear transfer as a means of transgenesis. Viable Factor IX transgenic female lambs were derived, and shown to express high concentration of the recombinant protein in their milk. These now provide the prospect of recombinant Factor IX as a safe alternative to human serum derived protein for the treatment of Haemophilia B. Also reported are preliminary experiments to assess gene targeting in farm animals. An ovine HPRT targeting vector was constructed. Inactivation of the ovine HPRT locus was attempted using fibroblast cells capable of supporting development after nuclear transfer.

Working dogs contribute to many human endeavours. However, minimal research exists into Australia’s largest group of working dogs – the livestock herding dog. This knowledge gap exposes the sector to the risks of sub-optimal efficiency, compromised productivity and unacceptable animal welfare outcomes. This thesis aims to address this void by characterising the problem of livestock herding dog wastage and contributing to the incremental process of improving management, selection and breeding practices. Data from a questionnaire completed by 812 livestock herding dog owners on 4,027 dogs revealed that livestock working dogs typically provide a lifelong working contribution valued at approximately A$40,000, representing a 5.2-fold return on investment. At least 20% of livestock herding dogs are culled prematurely from work. Behavioural causes were cited for 89% of these failures. Management and owner characteristics associated with failure rates included; acquisition practices, housing methods, training approach, exercise frequency and owner personality and attitude to investment in their dog. To identify traits important to success, a selective sweep analysis comparing the genomic haplotype architecture of working and show Kelpies was undertaken. In the working Kelpie, a selective sweep spanning three megabases on chromosome 3 was identified in the region of genes related to fear-memory formation and pain perception. The Herding Dog Assessment Form - Personality (HDAF-P) was devised to collect behavioural data on herding dogs. Application of the HDAF-P to 261 working Kelpies provided a database of behavioural scores for 17 traits salient to working ability with those correlated most strongly to the owner’s assessment of overall ability being revealed as; initiative (T = 0.42, p < 0.001), intelligence (T = 0.38, p < 0.001), persistence (T = 0.38, p < 0.001), confidence (T=0.37, p < 0.001) and calmness (T=0.32, p < 0.001).

Thesis (M.S.)--West Virginia University, 2001.<br>Title from document title page. Document formatted into pages; contains vi, 46 p. Vita. Includes abstract. Includes bibliographical references (p. 29-30).

Livestock production characteristics on the Navajo Reservation were studied to quantify and characterize herd demographics, feeding practices, management practices, marketing practices, and attitudinal orientations of producers. A stratified random (by grazing Agency) sample of the population (n = 10,000) yielded 125 possible respondents from each Agency. Face to face interviews were conducted by Navajo district grazing committeemen in the fall of 1997 for a total of 257 completed surveys. Navajo livestock producers were subsistence-level producers, who battled low birthing rates, slightly elevated mortality rates, diminished resource capacity, and challenges to economical feeding regimes. Most Navajos believed that livestock were an important part of their family's financial well-being; the Reservation was overgrazed; and that Navajos should be allowed to fence their land over their neighbors' objections. Navajo livestock production can be improved through education and greater articulation of the resource base. More detailed data collection is warranted to provide greater insight into production characteristics.

Thesis (Ph.D.) -- University of Glasgow, 2002.<br>Ph.D. thesis submitted to the Division of Infection and Immunity, Faculty of Biomedical and Life Sciences, University of Glasgow, 2002. Includes bibliographical references (p. 163-202). Print version also available.

The purpose of the work was to gain an understanding of the factors that influence household decision-making on the allocation of household resources and how these impact on the ability to own and successfully look after livestock. Livestock keeping dynamics were examined in terms of factors such as herd structures, production parameters, the ways in which households acquired and lost livestock and the characteristics of households entering and leaving livestock keeping. The study was undertaken in Funyula and Butula Divisions in Busia, Western Kenya and was carried out by means of a two-year longitudinal survey. Both quantitative and qualitative data collection methods were employed in the form of questionnaires and Participatory Rural Appraisal (PRA) exercises. Busia district has a typical smallholder crop-livestock production system with most households relying on crops as their main livelihood strategy and livestock being kept as a means of income diversification. The majority of animals entering livestock holdings were born into the holdings and there was only a 3% increase in the number of livestock keeping households over 2 years. Households purchasing animals generally bought the same species as they had sold. The proportion of animals lost through death ranged from 27% to 33% among the all livestock species and the majority of these deaths were disease related. A quarter of cattle sales were directly attributed to disease and between 5% and 7% of cattle and small ruminants were sold because they were ‘unproductive’, a factor that can often be linked to the presence of disease. Livestock disease episodes were higher during the long rains than the dry season, but more money was spent during the dry season when numbers of disease episodes were low. The provision of credit to farmers would help enable farmers make the initial investment in livestock and in the appropriate management of their animals.

In his classic study, Man and the Natural World (1983), Keith Thomas assumed and asserted that by 1800 the inhabitants of English cities had become largely isolated from animal life. My research challenges this assumption by highlighting the prevalence and influence of horses and other four-legged livestock in London in the period 1714–1837. This study represents a deliberate shift in historical enquiry away from the analysis of theoretical literature and debates concerning the rise of kindness and humanitarianism, towards the integration of animals into wider historiographies and a demonstration of how animals shaped urban life. Reasserting the need to unbound the social, my research places human interactions with non-human animals centre stage in London’s history to reassess key issues and debates surrounding the industrial and consumer revolutions; urbanization and industrialization; and social relations. Following an introductory section, Chapter one assesses the role played by urban husbandry in feeding the metropolitan population and asserts that Hanoverian London was a thriving agropolis. Chapter two challenges and complicates the orthodox assumption that steam substituted animal muscle power in the industrial revolution and asserts that equine power helped to make London a dynamic hub of trade and industry. Chapter three examines the metropolitan trades in meat on the hoof and horses. These were significant features of the consumer revolution and major sectors of the British economy which impacted heavily on London life. Chapter four asserts that equestrian recreation played a powerful role in metropolitan culture, both promoting and acting as an alluring alternative to, sociability. Chapter five examines the heavy demands which horses and other livestock placed on metropolitan infrastructures, and assesses the city’s remarkable investment in these animals. In my conclusion, I consider the significance of recalcitrant interactions between plebeian Londoners and non-human animals.

The purpose of this study is to investigate and provide a better understanding of the processes of Bedu livestock marketing system in the Badia of Jordan, particularly farmers' market behaviour, linkages to markets and their decision-making process. A mixture of quantitative and qualitative research methodologies were utilised. A stratified random sample of 193 Bedu farmers, and interviews with traders were applied. The whole region of the Jordan Badia and Research Development Programme was covered. The questionnaires were distributed and every farmer was interviewed by the researcher in the period from July to November 1995.A broad conceptual framework was employed to investigate quantitatively the interactions and dependencies between household conditions, socio-economic characteristics and livestock sales. These factors, which are usually outside the livestock enterprise, are important in household marketing decision-making in relation to time and place of sale, and reasons for sale. The results of this study indicate: Regarding farmers' marketing behaviour, marketing decisions are related to a household's demand for cash, and environmental factors such as the high cost of production, disease, unstable government policy, household characteristics, and labour capacity. The most important of these factors is to generate cash to buy feed or to reduce costs and eliminate the risk of disease. Most households with fewer than 100 head of sheep were more restricted in their sales decisions than households with larger flocks.

3 pp.<br>Frequently asked questions and answers regarding the Arizona Seasonal Pass application. Any Arizona resident exhibiting cattle, goats, sheep, or swine at any Arizona show or fair is required to obtain a Seasonal Pass.

Die Nutzung von Biomasse als Nahrungs- und Futtermittel sowie als Rohstoff geht mit einem erheblichen Eingriff in biochemische Kreisläufe einher. Die Nutztierhaltung beansprucht dabei den Großteil der ökonomisch genutzten Phytomasse und dominiert Stoffströme in der Landwirtschaft. Während bereits der gegenwärtige ökologische Fußabdruck von tierischen Erzeugnissen Anlass zur Sorge bietet, wird die globale Nachfrage nach Fleisch, Milch und Eiern im Zuge von Bevölkerungswachstum und steigenden Einkommen voraussichtlich weiter zunehmen. Die vorliegende Arbeit untersucht die wechselseitigen Zusammenhänge zwischen Tierhaltung und Umwelt im Kontext globaler Wandlungsprozesse und adressiert Unsicherheiten auch in Bezug auf gegenwärtige Umweltauswirkungen. Im Rahmen der Dissertation wurde das räumlich explizite ökonomische Landnutzungsmodell MAgPIE (Model of Agricultural Production and its Impact on the Environment) um eine detaillierte Darstellung des Nutztiersektors erweitert. Die Modellsimulationen unterstreichen das Potenzial, sowohl durch eine Änderung der Ernährungsgewohnheiten als auch der Produktionsweise von tierischen Erzeugnissen landwirtschaftliche Stoffströme und Landnutzung deutlich zu beeinflussen sowie Stickstoffverluste und Emissionen von klimaschädlichen Gasen zu verändern. Moderate Produktivitätssteigerungen können Waldökosysteme bewahren und Kohlenstoffemissionen vermeiden, führen allerdings auch zu Zielkonflikten zwischen dem Schutz aquatischer und terrestrischer Ökosysteme sowie zwischen Stickstoff- und Kohlenstoffverlusten. Zudem ziehen ehrgeizige Produktivitätssteigerungen großflächige Umwandlungen von Weide- zu Ackerland und damit eine Verringerung von Bodenkohlenstoffbeständen auf landwirtschaftlichen Flächen nach sich. Ein reduzierter Konsum tierischer Produkte in wohlhabenden Regionen trägt maßgeblich zum Erhalt der Wälder, der Vermeidung von Treibhausgasemissionen und der Verringerung des landwirtschaftlichen Wasserverbrauchs bei.<br>Human appropriation of biomass as food, feed and raw material interferes with key biochemical cycles. Livestock is at the epicentre of agricultural material flows and resource use, utilising the majority of the economically used plant biomass, substantially amplifying the agricultural nitrogen cycle, contributing to greenhouse gas emissions and water use, and dominating human use of land. While already today’s environmental footprint of livestock gives cause for concern, demand for meat, milk and eggs is expected to continue growing, driven by population growth, increasing incomes, and urbanization. Between the poles of current environmental externalities and the magnitude of the expected growth of the livestock sector, this thesis explores interactions between animal agriculture and the environment in the context of broad-scale developments such as globalization, technological innovation, rising food demand, and climate change and addresses gaps in our knowledge about current environmental impacts of livestock. For this aim, the spatially explicit economic land use model MAgPIE (Model of Agricultural Production and its Impact on the Environment) was extended by a detailed representation of animal agriculture. Model simulations demonstrate the large demand- and supply-side potential inherent in livestock production to transform biomass flows in agriculture and alter environmental externalities of food production. While moderate productivity gains in the livestock sector can reduce deforestation and emissions from land use change, trade-offs emerge between aquatic and terrestrial ecosystems, and between nitrogen and carbon losses. Moreover, ambitious productivity increases trigger large-scale pasture-to-cropland conversion that involves depletion of soil carbon stocks on agricultural land. A reduced consumption of livestock products in affluent regions considerably mitigates deforestation, carbon emissions and agricultural water consumption.

This study was performed in the Poroma community of the Oropeza Province, in the department of Chuquisaca. The Poroma community is characterized by a high poverty level among its members due to a number of different factors. Some of the major factors include: a restricted market, small farms, an absence of support systems, and a lack of support for agricultural development. This lack of support is seen in areas such as: research, roads, electricity, technical assistance, marketing systems, organization, and institutions that support rural development. Numerous studies on the production systems of farmers have described and analyzed the agricultural components but ignored the part livestock plays in the development of a rural production system. Due to this situation, this study has placed priority on the study of the livestock production system in the Poroma community. The objectives of this study are: to characterize and identify the components of the livestock production system; to establish the internal relations of the livestock production system; and to establish the relation between the livestock system and other systems present in the community. In order to accomplish the mentioned objectives, the participative research method was applied. The methods used are: Macro planning (participative prediagnosis) followed by case studies (micro planning). The techniques used to collect data are characterized as participatory. With these, we plan to involve farmers in the study. Some of the most important things are family and community workshops, participant observation, and informal discussions. The study investigated components of the livestock system such as: management, food, health, and production. Animal handling was observed to be completely free, like mating or birth, with men intervening very little in comparison to practices such as castration, branding, and grazing. The predominant race is the Creole. Delivery times are concentrated between the months of June and August (dry season) and November to December (rainy season). The main food source is the mountain where native species are used in regeneration. In general, the animals are browsers and the supplements provided are salt and bran. Only a few families control the health of their animals while the majority of families don’t control their health at all. This means that many problems exist with animal disease. The most common diseases in animals are: cattle: foot and mouth disease, anthrax, and diarrhea; sheep and goats: coenurosis; mules: angina; pigs: external parasites and cysticercosis; and birds: diarrhea. With respect to external parasites, the most severe in all the species are ticks and lice. The infrastructure for the animals in this area is not recommended because it does not offer the health conditions for their rusticity, let alone protect them from inclement weather. The products of the livestock system such as milk, meat, leather, manure, etc. are more commonly used for family consumption than for sale. The revenue earned by community members for this service is regular and is obtained at certain times of the year. Generally, they receive it at the beginning and end of each year as well as at fairs that are held in the area.

This thesis addresses the genetic characterisation of livestock breeds, a key aspect of the long-term future breed preservation and, thus, of primary interest for animal breeders and management in the industry. First, the genetic diversity and structure of breeds were investigated. The application of individual-based population genetic approaches at characterising genetic structure was assessed using the British pig breeds. All approaches, except for Principle Component Analysis (PCA), found that the breeds were distinct genetic populations. Bayesian genotypic clustering tools agreed that breeds had little individual genetic admixture. However, inconsistent results were observed between the Bayesian methods. Primarily, BAPS detected finer genetic differentiation than other approaches, producing biologically credible genetic populations. BAPS also detected substructure in the British Meishan, consistent with prior known population information. In contrast, STRUCTURE detected substructure in the British Saddleback breed that could not wholly be explained. Further analysis of the British Saddleback revealed that the genetic subdivision did not reflect its historical origin (union of Essex pig and Wessex Saddleback) but was associated with herds. The Rainbarrow appeared to be moderately differentiated from the other herds, and relatively lower allelic diversity and higher individual inbreeding, a possible result of certain breeding strategies. The genetic structure and diversity of the British traditional chicken breeds was also characterised. The breeds were found to be highly distinctive populations with moderately high levels of within-breed genetic diversity. However, majority of the breeds had an observed heterozygote deficit. Although individuals clustered to their origin for some of the breeds, genetic subdivision of individuals was observed in some breeds. For two breeds the inferred genetic subpopulations were associated with morphological varieties, but in others they were associated with flock supplier. As with the British Saddleback breed, gene flow between flocks within the chicken breeds should be enhanced to maintain current levels of genetic diversity. Second, the thesis focused on breed identification through the assignment of individuals to breed origin. Dense genome-wide assays provide an opportunity to develop tailor-made panels for food authentication, especially for verifying traditional breed-labelled products. In European cattle breeds, the prior selection of informative markers produced higher correct individual identification than panels of randomly selected markers. Selecting breed informative markers was more powerful using delta (allele frequency difference) and Wright's FST (allele frequency variation), than PCA. However, no further gain in power of assignment was achieved by sampling in excess of 200 markers. The power of assignment and number of markers required was dependent on the levels of breed genetic distinctiveness. Use of dense genome-wide assays and marker selection was further assessed in the British pig breeds. With delta, it was found that 96 informative SNP markers were sufficient for breed differentiation, with the exception of Landrace and Welsh pair. Assignment of individuals to breed origin was high and few individuals were falsely assigned, especially for the traditional breeds. The probability that a sample of a presumed origin actually originated from that breed was high in the traditional breeds. Validation of the 96-SNP panel using independent test samples of known origin and market samples revealed a high level of breed label conformity.

Pig production in Malawi and in most of the developing countries is shifting increasingly from pasture or dirt lot to total confinement with improved housing facilities. Keeping pig level temperatures within the comfort zone in hot weather is a common problem in naturally ventilated intensive pig buildings. Automatically controlled natural ventilation (ACNV) has proved to be effective in reducing the problem of heat build up in pig houses and is becoming very popular. However, a method for reducing summer temperatures at animal level in non-automated naturally ventilated intensive pig buildings has not been developed. An attempt was made to develop a natural ventilation system which would maximise the cooling effect of wind at animal level by manual control in buildings suitable for the Tropics. The research project was conducted in three stages: (1) air flow pattern studies, using 1:20 scale two-dimensional models, (2) wind tunnel testing, using three-dimensional, 1:20 scale models with simulated pigs, and (3) validation of results from the wind tunnel studies made with a 1:4 scale model, put out in the field. Air deflectors were used as a means of increasing the effect of wind on the ventilation pattern in the models. Monopitch, duopitch and offest gable models were tested in the water table, and monopitch models were tested in the wind tunnel. The use of air deflectors in monopitch and offset gable models showed a marked increase in airflow towards the animal zone area and a reduction in the difference between the surface temperature of the model pigs and the outside air temperatures. The deflectors improved the performance of the models by about 10% with the front orientation and about 20% with the rear orientation. In the duopitch model an increase in the roof overhang improved flow circulation on the leeward side. The use of air deflectors also improved flow circulation on the leeward side. The wind speed and air temperature at the experimental site for the 1:4 scale model were used to validate the results from the wind tunnel tests. The measured temperature values showed similar response curves to the predicted values. Temperature differentials increased with an increase in the angle of the deflector.

Genome mapping is in the forefront of interest among both plant and animal breeders, enabling the relationship between genes, genome structure and function to be investigated in addition to identifying the location of genes. The prerequisite of a linkage map of the genome is the availability of a large number of highly polymorphic and informative marker loci which are evenly distributed throughout the genome. Microsatellite loci provide the unique class of markers which overcome many of the difficulties associated with the other market types. The availability of a detailed genetic map of the bovine genome could enhance the genetic progress in cattle breeding programmes through the identification of loci affecting traits of economic importance. Other potential applications of genetic markers include their use in confirmation of parentage, individual identification, germplasm evaluation and identification of disease loci. In this thesis, microsatellite markers are investigated in three areas, a) parentage verification and individual identification b) study of phylogenetic relationship and c) mapping a lethal defect in Dexter cattle. a) Five highly polymorphic microsatellite markers CYP21, DRB3, FSHB, ETH131 and HEL6 were evaluated for parentage verification using 275 animals belonging to 15 breeds of cattle. Some breeds were found not be in Hardy Weinberg Equilibrium (HWE), the deviation being greatest in those breeds which had an excess of homozygotes. A new approach was developed for calculating the Probability of RAndom Sire Exclusion (PRASE) taking into account the deviation from HWE and linkage between markers, using observed genotype frequencies. Taken together, the linked markers, DRB3 and CYP1 gave a PRASE of 0.88 in all breeds with success ranging from 0.75-0.96. Including a third marker the PRASE was increased to 0.97, and with all five markers 0.99 or better was achieved for all the 15 breeds.

Silvopasture is a land-use management practice which intentionally integrates trees, forage, and livestock. It is increasingly prevalent in outreach and extension, yet considerations for adoption are complex. The implementation of a cost-share initiative for silvopasture created by the Natural Resource Conservation Service (NRCS) in Virginia in 2011 provides an opportunity for landowners to establish silvopasture systems on their properties, thus diversifying land management and income, as well as providing environmental benefits. However, research on who might adopt silvopasture and why is needed. For this research, a mail survey was distributed to 307 cost-share enrollees in NRCS' livestock limitation initiatives and 139 were returned (45.3%). The first objective of this survey was to gauge interest in two forms of silvopasture implementation: a) thinning a woodlot and b) planting trees in a pasture. Furthermore, the study was utilized to test which hypothetical benefits might increase a livestock producers' interest in either implementation form. Results show that respondents preferred thinning to planting but risk and uncertainty were perceived in both. Environmental outputs and assistance from technicians increased interest in both practices over economic benefits; however, livestock performance was most important. Literature on the topic aligns with findings and highlights that more research is needed to understand risk, environmental, and resource-related factors. The second objective was to measure interest in silvopasture and classify respondents based on their operational or their beliefs-based characteristics and assess which classification set mattered more. Results indicated that interest in silvopasture varied but the majority (60%) indicated they were either interested or very interested. Two-step cluster analysis was used to classify respondents based on their operational considerations and a combination of Exploratory Factor Analysis and K-means clustering was used to group livestock producers according to their beliefs on traditional and land-use values. A Kruskal-Wallis independent samples analysis for each classification revealed no statistically significant differences in the interest in silvopasture between operational groupings. Conversely, there were statistically significant differences in silvopasture interest according to beliefs-based classifications. These results suggest that operations of livestock producers do not matter as much as their attitudes and beliefs related to the practice. A cross-tabulation of the operational classification and beliefs cluster resulted in no correlation. Literature suggest both operational characteristics and producer beliefs may matter in agroforestry adoption, but that positive or negative correlation in terms of interest may vary.<br>Master of Science<br>Silvopasture is a agroforestry conservation practice that integrates trees, forage, and livestock in a managed system. The adoption of this practice is complex, though education on the practice has been increasing. A cost-share initiative for silvopasture was created by the Natural Resource Conservation Service (NRCS) in Virginia in 2011, which creates the opportunity to implement silvopasture systems on landowner properties. This system could lead to more diversification of land and income, as well as providing environmental benefits. However, more research is needed. A mail survey was sent to 307 NRCS cost-share enrollees who were managing livestock and 139 were returned. The survey had two objectives; the first was to measure interest in the two forms of silvopasture implementation: a) thinning a woodlot and b) planting trees in a pasture. Hypothetical benefits which might increase a livestock producers’ interest in thinning or planting for silvopasture was also measured. Results show that respondents had a preference for thinning over planting. Economic benefits were not as effective in increasing interest compared to environmental outputs and assistance from technicians; however, livestock performance was most important. Findings were aligned with literature on silvopasture and agroforestry but more research is needed. The second objective was to measure interest in silvopasture and classify respondents based on their operational or their beliefs-based characteristics and to see which classification set mattered more. Results indicated that interest in silvopasture varied but the majority (60%) indicated some level of interest. Statistical analyses were used to classify respondents based on their operational considerations and used to group livestock producers according to their beliefs on traditional and land-use values. Outputs showed no statistically significant differences between operational groupings and their interest in silvopasture. There was a statistically significant difference in silvopasture interest according to beliefs-based classifications. These results indicate that the operations of livestock producers do not matter as much as their attitudes and beliefs on the practice. Previous literature indicates that both operational characteristics and producer beliefs may matter in agroforestry adoption, but interest may vary regardless.

<p>This study compares the energy utilization of two systems for producing cattle of desirable slaughter weight and grade from weanlings. Both systems produce beef cattle as a primary output; various types of baled hay are produced as a secondary output. One system uses generally accepted, "best management practices" while the other uses experimental, sustainable agriculture techniques. Since the adoption of new practices in agriculture often hinges on economics, an economic comparison is also presented.</p> Beef produced in the sustainable system required 32% less energy per kilogram than that produced in the conventional system. However, baled alfalfa produced in the sustainable system required 8% more energy per kilogram than the alfalfa grown in the conventional system. When all types of hay were considered, the sustainable system used 7% more energy to produce one kilogram of baled hay. To compare the energetics of the two systems on a whole farm basis, the amount of energy required to produce one dollar of return was calculated. The sustainable system required 12.4 megajoules to produce one dollar of return, while the conventional system required 17.1 megajoules to produce the same return. Although economic returns on beef and alfalfa production were comparable in the two systems studied, the conventional system showed greater returns on the whole farm, due to a greater export of baled hay.</p><br>Master of Science

Straw price increases due to biofuel demand have created a perceived need within the agricultural industry to investigate and develop alternative bedding materials for housing ruminant livestock. This thesis addresses the suitability of woodchip, as such an alternative, indoor bedding material for livestock, focusing particularly on management of the soiled bedding, its nutrient composition, its use as an agronomic resource and its economic viability within the Welsh farming sector. In all studies, straw was used as the benchmark to which the woodchip treatments were compared. Many studies have investigated the use of woodchip in out-winter pads (OWP), but the material’s indoor performance and in particular, its potential for re-use, is not well documented. Two independent housing trials, both including sheep and cattle, were conducted. The first trial (ADAS) assessed the effect of different initial woodchip moisture contents on the performance of the bedding material and its subsequent composting. The second trial (IGER) evaluated the effects of hay and silage diets on woodchip’s bedding and composting performance. The ADAS trial showed that woodchip’s absorbency capacity and physical shape were critical in determining its bedding and composting success. In comparison to differences determined by bedding materials and livestock characteristics, the IGER trial suggested that dietary inputs had little influence on the woodchip’s bedding and composting performance. Overall, the results indicate that composting of spent woodchip bedding was less effective than that of straw bedding, due to the lack of available N which limited microbial activity. The limited breakdown of the woodchips during composting, however, does potentially allow the re-use of the bedding materials for further housing cycles. Barley sown growth trials, amended with composted bedding materials showed that woodchip composts yielded reduced biomass in comparison to conventional NPK based fertilisers and straw bedding compost. When the coarse woody fraction of the compost was removed (>8 mm in diameter), leaving just the fine (< 8mm) nutrient-enriched fraction, plant growth performance was slightly enhanced at application rates equivalent to 100 t ha-1. Estimates of N loss from woodchip treatments were high during housing, but limited during composting due to a generic lack of available nutrients, compared to straw. Using economic modelling, a cost/benefit analysis of woodchip bedding versus straw showed that woodchip is more cost efficient than straw on the condition it is re-used. In summary, the thesis concludes that woodchip is a potentially viable alternative to straw bedding for Welsh farmers, on condition of specific management practices. Future work is required to identify and mitigate N losses during the woodchip bedding phase.

De nos jours, l'épidémiologie des bactéries multi-résistantes a évolué et ne se limite plus aux milieux hospitaliers. En effet, les animaux sont désormais considérés comme d’importants réservoirs de bactéries multi-résistantes, notamment des Bacilles à Gram négatif sécréteurs de bêta-lactamases et/ou résistant à la colistine. L'émergence de ces bactéries chez les animaux est due principalement à l’utilisation excessive d’antibiotiques en tant que prophylaxie et facteurs de croissance. Le transfert d’organismes multi-résistants aux antibiotiques provenant d’animaux vers les humains est un problème majeur pouvant entrainer de graves infections. La transmission zoonotique se fait par contact direct/indirect mais aussi par voie environnementale. Au Liban, plusieurs études ont été menées dans les hôpitaux et ont montré une prévalence élevée de bactéries multi-résistantes. En revanche, ces études sont rares dans le milieu vétérinaire. Le but de ce travail de thèse est de décrire l'épidémiologie des organismes multi-résistants dans les animaux d’élevage destinés à la consommation au Liban. Le typage des bactéries par MLST et le séquençage du génome entier ont été utilisés pour décrire la prévalence des organismes multi-résistants et les mécanismes de résistance chez les souches isolées. Nous pouvons ainsi conclure que les élevages de poulets et de porcs sont de puissants réservoirs de gènes de résistance BLSE et mcr-1 au Liban. La dissémination de la résistance semble être polyclonale et liée à la propagation de plasmides porteurs de gènes de résistance. Par conséquent, l'utilisation de la colistine en médecine vétérinaire au Liban doit être interdite<br>Nowadays, the epidemiology of multi-drug resistance has changed and is no more confined to the hospital settings. Food producing animals are increasingly regarded as potent reservoirs of multi-drug resistant organisms i.e. beta lactamase producers and colistin-resistant Gram-negative bacilli. The emergence of multi-drug resistance in animals is thought to be mainly driven by the overuse of antibiotics as growth promoters and prophylaxis. The dissemination of resistant organisms in animals is sparked by the concern of being transferred to humans where they can be candidates for infections with limited therapeutic options. The zoonotic transmission of resistant organisms from animals to humans occurs mainly via direct/indirect contact but also via environmental routes. In Lebanon, several studies were conducted in hospitals and showed a high prevalence of multi-drug resistance; unlikely, these studies are scarce in animals. The aim of this thesis research was thus to describe the epidemiology of multi-drug resistant organisms in Lebanese Livestock Multi-locus sequence typing and whole genome sequencing were used to describe the prevalence of multi-drug resistant organisms and the corresponding mechanisms of resistance in the isolated strains from chicken, pigs, farmers and environment. Chicken and swine farms showed to be potent reservoirs of ESBL and mcr-1 genes in Lebanon. The dissemination of multi-drug resistance appears to be multi-clonal and related to the spread of plasmid carrying resistance genes. Colistin use in veterinary medicine in Lebanon should be banned

Development of transfrontier conservation areas (TFCAs) in southern Africa depends, among other, on the ability of stakeholders to find practical and sustainable solutions for wildlife‐livestock integration in the conservation landscape. Due to the presence of buffalo Syncerus caffer in most of the TFCAs in southern Africa, foot‐and‐mouth disease (FMD) has to be controlled in susceptible livestock species sharing the rangelands with wildlife. Conventional FMD control measures act as an additional burden on communal livestock producers and may hamper rural development and wildlife‐livestock integration even further. However, commodity‐based trade in the form of an integrated approach to the control of both food safety and disease risk along the entire beef value chain has been proposed as a more favourable alternative for ensuring market access for beef produced at the wildlife‐livestock interface. Such a non‐geographic based approach could allow for trade to continue despite high risk of FMD if appropriate disease risk and food safety measures are implemented by farmers and subsequent role players along the value chain and hence, could promote greater wildlife‐livestock compatibility.<br>The objective of the present study was to analyse beef production, health and trade systems of farmers at the wildlife‐livestock interface within foot‐and‐mouth disease (FMD) protection zones in order to identify challenges, risks and limitations that may limit compliance with proposed commodity‐based trade prerequisites as well as value chain participation. Based on the findings of this study a holistic, integrated approach is proposed at the village level that could be implemented to serve as an incentive for equitable participation by farmers whilst 1) addressing the risks and limitations of a farming system, 2) ensuring greater wildlife‐livestock compatibility, and 3) promote consistent market access by fulfilling the requirements of an integrated value chain approach based on commodity‐based trade standards.<br>A farming systems approach was used to investigate beef production, health and trade systems in FMD protection zones mainly within the Zambezi Region (ZR) of Namibia, which is situated within the KAZA TFCA (Kavango‐Zambezi Transfrontier Conservation Area), but also the Mnisi study area (MSA) in South Africa adjacent to the Great Limpopo Transfrontier Conservation Area (GLTFCA). A combined qualitative and quantitative approach was used to assess and describe farmers’ perceptions in selected study areas about beef production, trade, and wildlife conservation. Secondary data obtained from state veterinary services, the Meatco abattoir in Katima Mulilo, as well as previous studies were analysed and modelled to describe spatial‐temporal trends in trade as well as cattle distribution in relation to resource availability.<br>The results indicate that beef production systems in some of the most remote areas of the ZR as well as in the MSA resemble a typical low‐input low‐output production system, mainly due to the high level of risk farmers had to cope with and the limited opportunity to offset losses. The major challenges within livestock farming in all the areas studied were animal diseases, grazing competition, predation, stock theft and contact with wildlife, although the importance of each varied between study areas. Herd size effect in the MSA significantly explained the variation in attitude towards trade, production and management of cattle between farmers with below average and farmers with above average herd sizes. In the MSA, home slaughter contributed significantly more to direct household food security in households with larger herd sizes than in households with smaller herd sizes, and in the ZR farmers with smaller herd sizes were discouraged from participation in formal trade.<br>The attitudes and perceptions of farmers In the ZR towards wildlife and conservation often varied between survey areas as a consequence of the variation in the geophysical properties of the landscape, proximity to conservation areas, as well as the form of the interface with conservation areas. The perceived spatial‐temporal movement of buffalo varied between survey areas in the ZR. However, the frequency and nature of buffalo‐cattle interaction was generally high and intimate. Most farmers associated buffalo with risk of disease, especially FMD, but some were more concerned about grazing competition and the negative effect on husbandry practises. Farmers readily deployed traditional risk mitigation tactics in the form of kraaling at night and herding at day to control the movement of their animals and to reduce risks. Herding was found to be a potential strategy to specifically mitigate cattlebuffalo contact despite the lack of evidence that an overall strategic approach to herding exist. Although the majority of farmers in the ZR were in favour of conservation and its benefits, the negative impact of increasing wildlife numbers on farmers’ attitudes was an indication that the generally positive sentiment was changing and may in future deter conservation efforts.<br>Indications are that the cattle population in the ZR at its estimated density and distribution had reached the ecological capacity of the natural resource base in the ZR and animal performance and survival was therefore subjected to increased variability in resource availability linked to climate change. The cattle population’s existence at ecological capacity and the inability of farmers to offset the loss of condition in the dry season with supplementary feed were reflected in the changes in carcass quality and grades across seasons. However, there was sufficient forage produced in the ZR to sustain animal performance to some extent throughout the year, but those areas with surplus forage existed beyond the assumed grazing range around villages and perennial rivers where most cattle and wildlife concentrate. The future ability of farmers to access such underutilised grazing resources in order to strategically counter the negative consequences of climate change and growing wildlife numbers could be an important coping and risk management mechanism linked to commodity‐based trade and sustained animal quality.<br>Regular FMD outbreaks had a significant impact on the consistency with which the Meatco abattoir in the ZR operated between the years 2007‐2011, with negative consequences to both farmers and the abattoir itself. It was found that the formal trade system in the ZR discriminated against farmers with below average herd sizes, and that the disposition held by farmers with smaller herd sizes are most significant in areas further than approximately 55km away from quarantine camps. Vegetation type and possible contact with buffalo or previous FMD outbreaks in the area did not significantly affect market participation nor off‐take rates at a crush‐pen level in the ZR. The negative effect that distance from a quarantine station had on formal off‐take rate and the level of sales to Meatco at crush‐pen level, was the most significant in the winter months and crush‐pens situated beyond 55km from a quarantine station. The results indicate that the trade range of the Meatco abattoir was less than its trade threshold which contributed to its struggle to sustain throughput and profitability.<br>Finally the loss of income farmers experienced in both the ZR and the MSA during simultaneous FMD outbreaks in the year 2012 was quantified, as well as the impact it had on livelihoods in the ZR. A commodity‐based trade approach may have reduced the impact on farmers’ income significantly. However, we farmers are unable to comply with the proposed requirements for mitigating risk and ensuring food safety and quality in such communal systems in the absence of interventions to build the necessary capacity and awareness. It is recommended that at the wildlife‐livestock interface such as those investigated in this study, an integrated value chain approach to trade could serve as a catalyst to incentivise and enable farmer participation in holistic, integrated rangeland and livestock management practises that will promote conservation and rural development.<br>Thesis (PhD)--University of Pretoria, 2016.<br>The Institute for Tropical Medicine, Antwerp, Belgium<br>University of Pretoria<br>National Research Foundation of South Africa<br>Veterinary Tropical Diseases<br>PhD<br>Unrestricted

<p> Among the vast diversity of plants in the mid-South to which grazing livestock are exposed, there is a need to address certain species that are potentially harmful to livestock health and production. Field and greenhouse experiments were conducted on endophyte-infected tall fescue [<i> Schedonorus arundinaceus</i> (Schreb.) Dumort = <i>Lolium arundinaceum </i> (Schreb.) Darbysh.], a cool-season perennial forage, and perilla mint, (<i>Perilla frutescens</i> (L.) Britton) an herbaceous annual, to determine management techniques and control measures for healthier pasture and livestock systems. When seedheads reached maturity, spring and autumn glyphosate applications at 1.68 kg ae ha^&ndash;1, coupled with autumn tillage and summer and winter cover crops effectively reduced tall fescue coverage to &lt; 27% by 10 months after initial treatment (MAT) following a single year of management. If seedhead maturity is inhibited prior to first glyphosate application, tall fescue was reduced to &lt; 1% coverage 10 MAT. Despite seedhead suppression, at least 78% increase in coverage occurred in 24 months from remnant populations suggesting two years of renovation is required. Forage soybeans proved to be a valuable cover crop that maintained nutritive quality and mean dry matter yields of 5487 kg ha^&ndash;1 across two years. Tall fescue seedheads were suppressed below 14% coverage (> 68% visual control) by nicosulfuron + metsulfuron (20 + 5 and 40 +11 g ai ha^&ndash;1), imazapic (26 and 53 g ai ha^&ndash;1), and sulfosulfuron (53 g ai ha^&ndash;1) at 90 DAT. Reduction in forage heights may be expected, but was not consistently reduced when compared to untreated plots across locations. </p><p> To control perilla mint, postemergence applications of aminocyclopyrachlor blends, glyphosate, picloram + 2,4-D, aminopyralid + 2,4-D, and 2,4-D alone provided superior control when applied prior to the plant&rsquo;s reproductive growth stage. Picloram + 2,4-D also provided in-field soil residual activity and the most effective preemergence control, followed by aminocyclopyrachlor + chlorsulfuron, pendimethalin, and aminopyralid + 2,4-D for at least 141 DAT. Seed from weedy populations in north Mississippi tend to germinate in a range of night/day soil temperatures from 10/15 C to 25/30 C. Therefore, effective preemergence treatments should be applied by mid- to late- February in this region.</p><p>

This thesis describes a series of four experiments designed to evaluate the role of the supply of protein in livestock grazing high quality pasture during mating and during pregnancy. The first two studies investigated the effects of high crude protein content of spring or autumn re-growth pasture on the reproductive performance of dairy cows and of ewes at mating. The last two studies investigated how the dietary supply of protein, body condition and their interactions contribute to the breakdown of immunity during the peri-parturient period in ewes and investigated underlying endocrine mechanisms. In the first study (Chapter 3) cows were blood sampled via the tail vein during the breeding period in spring. Plasma was then analysed for urea concentration. Cows with high plasma urea (HPU) or low plasma urea (LPU) were defined as those with plasma urea concentrations of ≥ or < 44.9 mg/dl respectively. Lactating cows (n = 200) were also categorized into high milk producers (HMP) or low milk producers (LPM) relative to an average daily yield of 26.6 l/d. Pasture clipping showed an average pasture CP (crude protein) content of 223 g/kg DM. Concentrations of plasma urea ranged from 26.6 to 64.4 mg/dl. No correlation was observed between plasma urea concentration and either reproductive indicators or milk parameters. Mean blood urea concentration of HPU cows was 50.8 compared to 38.5 mg/dl in LPU cows. There was a trend for more animals (P = 0.09) in the HPU group than in the LPU group not to return to oestrus. Cumulative pregnancy rate in HPU and LPU was similar except at week 6 after the start of mating when more (P < 0.01) HPU than LPU cows were pregnant. Calving to conception interval, calving interval and interval between conception and first service were similar (P > 0.05) between HPU and LPU cows. Gestation length, calving rate, milk yield and milk components were also similar (P > 0.05) between LPU and HPU cows. There was no difference (P > 0.05) in plasma urea concentrations between HMP and LMP milk producers. However, calving to conception interval, interval between calving and first service and calving interval were longer (P < 0.001), submission rate higher (P < 0.001) and NRR (Non-return rate) higher (P < 0.05) in LMP than HMP. The number of services, the interval between first and second service, gestation length and CR (calving rate) were similar (P > 0.05) between HMP and LMP cows. HMP had lower (P < 0.001) milk protein and fat concentrations than LMP cows. This information indicates that, despite the fact that plasma urea was consistently higher than levels in the literature which have been associated with reduced fertility in dairy cows; no impairment of reproductive performance was observed. In the second experiment (Chapter 4) mature and dry Coopworth ewes were blocked by weight, body condition and previous prolificacy (high, HP vs low twinning frequency, LP) into two groups and thereafter randomly allocated to diet which were designed to provided either 1) high protein (163 g/kg DM, ryegrass/red clover pasture, HPP) or low protein (119 g/kg DM, hay and barley grain, HB) supply at joining. These were designed to provide high and low plasma urea concentration. Over a period of 17 days, ewes recorded as mated were examined by laparoscopy, at which time there was no difference in blood urea concentration (58.6 vs 56.1 mg/dl) between HPP and HB groups. Fifty days after the start of joining the number of foetuses present was counted using ultrasonography. As a consequence of lack of difference in the plasma urea concentration, irrespective of treatment group, individual animals were categorized into high (HU) and low plasma urea (LU) status based on whether plasma urea concentration was higher or lower than the sample mean of 51.5 mg urea/dl. Lambs which weighed greater than the mean plus one standard deviation for their litter size were classified as oversize. Ovulation rate and conception rate were similar (P > 0.05) between HPP and BH and between HU and LU ewes. Ewes with previous high reproductive performance (HP) as would be expected had higher ovulation rate (P < 0.001) and conception rate (P < 0.01) than LP ewes. Embryo losses was not (P = 0.06) different between HB and HPP ewes. Urea category (HU vs LU) did not (P > 0.05) influence embryo mortality. Foetal loss, neonatal loss, total reproductive loss and mean lamb birth weight was were not affected by diet, nor urea category (P > 0.05). Single ovulations had tended (P = 0.08) to contribute to higher embryo loss compared to multiple ovulations, and, single foetuses suffered higher (P<0.001) losses compared to multiples. While the study did not achieve large differences in plasma urea concentrations between diets, the levels of plasma urea operating were high yet reproductive wastage rates were similar to those recorded in the literature. Together with similar apparent lack of effect on a high plasma urea environment, the data suggest either that previous findings from controlled studies have a more complex aetiology or that pastoral animals can adapt to high tissue ammonia/urea status. The third trial (Chapter 5) was designed to provide information on the supply of amino acids to the abomasum from protein supplementation which have previously been found to overcome dietary scarcity associated with limitation of peri-parturient increase in FEC. Twin-suckling ewes were fitted with rumen and abomasal cannulae and grazed a ryegrass/clover sward (C) or the same sward but with a 500 g/h/d protein supplement (S). The trial was designed as a cross-over with two 14 day adaptation periods followed by two five-day digesta-sampling periods. All ewes were treated with anthelmintic 14 days after lambing. Weekly analysis of blood glucose was carried on whole blood and analysis of amino acids in plasma. The flows of amino acids (AA) and dry matter (DM) at the abomasum were measured during both sampling periods using intra-ruminally infused markers. Live weight and faecal egg count (FEC) were recorded weekly. Diurnal variation in AA flow at the abomasum peaked between 12:00 and 15:00 h and was greatest in S ewes. Flows of AA, including DAPA, were increased by supplementation by 16%, while sulphur amino acids (SAA) were the most enhanced (by 21%) and flows of leucine, lysine, glutamine and aspartate were increased by about 20%. There were significant time effects in rumen and abomasal pH (P < 0.01; in both cases in both periods) reflecting increase in pH after 09.00 h. During Period II, rumen pH in digesta of C ewes was significantly higher (P < 0.001) than that of S ewes (6.7 ± 0.05 vs 6.4 ± 0.05 for C and S ewes, respectively). Plasma AA concentrations (P < 0.01) were lower in S ewes 21 days after parturition, but similar (P > 0.05) to those of C ewes at other times. Forty-three days after lambing (after cross over), the order was reversed as plasma methionine and cysteine concentrations of C ewes became low (P < 0.05). These changes in plasma AA were accompanied by changes in body condition score between day 23 and 70 post-partum whereby C ewes lost more body condition than S ewes. There was evidence for a lower FEC in S ewes, being 46 vs. 670 epg, respectively for S and C groups (P = 0.08) 21 days after anthelmintic treatment. There were higher (P < 0.05) blood glucose levels in C compared to S ewes at day +35 relative to lambing which was reversed and significantly higher (P < 0.01) for S ewes by day +56 from lambing (after treatments were reversed). There was no significant effect of treatment on live weight and lamb performance. There are limited data in amino acid supply on lactating ewes on pasture and the present study contributes additional information on the supply of amino acids at the abomasum. The prediction that flow rates that sulphur amino acids may have been enhanced to the greatest degree could be significant since sulphur amino acids are needed for the synthesis of glutathione for immune response. It can be calculated that supplementation to supply the quantities of S-amino acid at pasture would be needed, since it would not be possible for sheep to increase pasture intake to achieve similar S-amino acid flow. Increase in bypass amino acids in S ewes at certain times in the day probably suggests influence by protein supplementation at certain times of the grazing cycle. Reduced plasma free amino acids at day +21 relative to lambing, may indicate sparing of body protein breakdown by protein supplementation. However, the difference in blood glucose on day 35 and day 56 may indicate re-adjustment of hormonal settings, responsible for nutrient partitioning. The last study (Chapter 6) used ewes during the peri-parturient period on pasture. Eighty pregnant ewes were allocated into four groups balanced for anticipated number of lambs. Group 1 had a high body condition score (BCS) of 4.0 which was maintained throughout pregnancy by pasture allowance (HM; n = 20). Group 2 (n= 40) had medium body condition (BCS 3.0) and were split into two subgroups; one was offered pasture to allow gain of condition (MH; n = 20) and the second allowed to lose condition by offering a low grazing allowance (ML; n = 20). Group 3 were thin ewes (BCS 2.4) and pasture allowance was designed to maintain this condition (LM; n = 20). These feeding regimes were maintained for 3 weeks from week -8 of pregnancy. During week -5 to -4 all ewes were acclimatized to a protein supplement (60 g/d). A glucose tolerance test (GTT) was conducted during week -4 after which half of the ewes in each group were offered a protein supplement at the rate of 500 g/d, creating –S and –NS groups. During wk -2, a second GTT was carried out. Animals were treated with an anthelmintic 3 wks before lambing, and were then challenged with a dose of 10 000 Teladorsagia circumcincta larvae on weeks -2 and -1 relative to lambing. Weekly recording of FEC, live weight and body condition was carried out. Lambs were weighed within 24 h of birth and again at 44 and 65 d of age. Computed tomography body scanning was carried out on ewes at weeks -8, -3 and +8 relative to lambing. There were no differences (P > 0.05) in lamb performance due to body condition or protein supplementation. FEC of all groups was low (≈ 9 peg) and there was no (P > 0.05) significant difference between ewes of different body condition or due to effects of protein supplementation. Ewes bearing/bearing multiple lambs had the highest FEC at day -32 and +12 relative to lambing, which was significant (P < 0.05) on the latter date. There were no significant effects of supplementation on parasite status. There were differences in basal plasma glucose concentration between groups (P < 0.001), being highest in HM/S and least in ML/NS ewes and was generally higher (P <0.001) during GTT 2 than GTT 1. Ewes carrying a single foetus had higher (P <0.001) basal glucose than those carrying multiple lambs (2.2 vs. 1.7 mmol/L, respectively). Other plasma glucose response indexes were similar (P <0.05) between groups. There were differences in insulin responsiveness between groups (P < 0.001), being highest in MH/S and least in ML/S ewes. Insulin responsiveness tended (P = 0.06) to be lower during GTT 1 than GTT 2, but was higher (P < 0.01) in ewes carrying singles than multiples. There was tendency for higher though non-significant, basal insulin concentrations in HM ewes. Insulin trends over time after glucose infusion suggest greater insulin response at GTT 1. Basal insulin was not correlated with CT muscle weight. Despite differences in body muscle mass at the start of the trial and differences induced by nutrition during late pregnancy, positive gains in muscle mass occurred during early pregnancy and muscle mass was similar in all groups by day 56 of lactation. Animals with greatest fat content at parturition (HM) mobilised the greatest amount and those with least fat (LM) deposited fat during lactation. Further experimentation may consider the use of the hyperinsulinemic-euglycemic clamp approach to more precisely estimate whether hormonal re-setting through insulin resistance may be involved in relaxation of immunity during the peri-parturient period.

Thesis (M.S.)--West Virginia University, 2009.<br>Title from document title page. Document formatted into pages; contains vi, 122 p. : col. ill. Vita. Includes abstract. Includes bibliographical references (p. 51-53).

The changing abundance and distribution of parasitic helminths has been identified as one of the greatest threats to animal health in the UK under climate change. This is due to the strong influence of abiotic conditions on parasites’ free-living stages. Planning adaptation and mitigation strategies requires predictions of parasite risk, and understanding of subtle interactions between abiotic conditions and parasite transmission. This requires development and application of a range of different modelling approaches. This thesis includes the first long-term forecast showing potential impacts of climate change on a parasitic helminth in the UK. By combining a correlative parasite risk model with UKCP09 climate projections, risk maps are generated identifying which areas of the UK are predicted to experience unprecedented levels of fasciolosis (liver fluke) risk in the future. Correlative models provide warnings of future risk, indicating where resources for monitoring and control should be targeted. To address more complex issues, and foresee consequences of subtle interactions between various components of a system under climate influence, a drive towards process-based mechanistic models is required. Consequently, a spatially explicit mechanistic model is developed, for the transmission of gastro-intestinal nematodes in a controlled grazing system. This allows investigation into how climate impacts on different elements of transmission. A non-linear relationship between climate change and parasite risk is revealed, with a distinct ‘tipping point’ in outbreaks when temperature driven processes exceed critical rates. This indicates that climate change could lead to sudden and dramatic changes in parasite risk. Through combining the models developed here with improved empirical data and a broader view of livestock systems, our understanding of future risks and opportunities can be increased. This will allow improved control of these physically and economically damaging parasites, reducing deleterious impacts on production efficiency and animal welfare.

5 pp.<br>Arizona youth livestock quality assurance and food safety: Trainers reference. Arizona youth livestock quality assurance and food safety: Youth manual. Feeding management for show lambs. Feeding management for show steers. Swine nutrition for show animals.<br>Illness or injury to a show animal may be preventable by following a few guidelines. Providing a clean and safe environment and properly feeding, watering, and vaccinating animals will help to reduce the risks of experiencing illnesses and injuries. Owners should also learn how to identify signs of health problems, such as sudden changes in behavior or appearance, and prepare a first aid kit for use in the event of an emergency. Also, being familiar with emergency treatment guidelines will help owners protect themselves, prevent further injury to the animal, and properly administer care to the animal if appropriate.

With the intense use of high throughput genomic technologies, our knowledge about the cattle and pig genomes has rapidly evolved. Over the last years, many investigations have been already carried out to identify major genes and mutations underlying different morphological, productive, and reproductive traits in cattle and pigs. This thesis is the result of research activities focused on the investigation of genomic features to find novel candidate gene markers associated with pigmentation in two Italian local cattle breeds (Reggiana and Modenese) and in an Italian heavy pig breed, the Italian Large White breed. In the first study that we proposed, we detected signatures of selection in the genome of these two autochthonous cattle breeds using genome-wide SNP information in comparative FST analyses. Results show top FST values detected for the melanocortin 1 receptor (MC1R) gene region on BTA18, and for the agouti signalling protein (ASIP) gene region on BTA13. The second aim of this thesis was to investigate the pigmentation process of the iris in the Italian Large White pig breed. This is a white-coloured breed not affected by albinism. For this aim, we carried out several genome-wide association studies using high density SNP datasets and designed to contrast groups of pigs with different colour of iris. The results indicated that the eye pigmented patterns, the total absence of pigmentation in the both eyes, and heterochromia iridis defect were associated with SNPs close to the SLC45A2 (on chromosome 16, SSC16), EDNRB (SSC11) and KITLG (SSC5) genes, respectively. In addition, other associated genomic regions with eye depigmented patterns were also identified. This thesis demonstrates how population genomic approaches designed to take advantage from the diversity between livestock genetic resources could provide interesting hints to explain pigmentation related traits not yet completely investigated in these species.

The livestock sector is facing a huge challenge trying to meet the increasing demand of animal products. To this end several efforts have been done to enhance animals’ performances, and nutrition provides a valuable asset. Animals’ performances can indeed be boosted through nutritional approaches, including both the application of technologies in a context of ‘precision nutrition’ and the administration of novel feed additives or feedstuffs with beneficial effects on animals’ health. The main aim of this thesis was to investigate 1) the proficiency of feeding systems for dairy cows (1st trial) and the suitability of sensor technology to ensure the fulfillment of cows’ nutrients requirement (2nd trial), and 2) the effectiveness of feed additives to improve animals’ health and consequently their performances (3rd and 4th trial). The first study investigated some aspects connected to the mixer wagon, and their influence on the preparation of the total mixed ration (TMR) for dairy cows. We evaluated how loading levels, cutting time, mixing time and their interaction can affect the homogeneity of the TMR along the feeding alley. The uneven distribution of the TMR along the feeding alley does not allow each animal to receive the same well-balanced diet, with the risk of not satisfying the nutritional requirements, finally impairing productive performances. Even though we identified the most efficient combination of loading levels, cutting, and mixing time, variations in the distribution of DM and NDF were observed, pointing out the necessity to investigate which other factors are influencing TMR preparation and distribution. In the second study we developed a system based on a microwave resonance sensor to optimize TMR preparation. Silages represent a large proportion of feeds included in the TMR, but their nutrient supply (on as fed basis) can vary among time due to moisture content fluctuations. For this reason, if their inclusion rate in the mixer wagon is not adjusted according to the actual dry matter (DM) content, ensuring the proper provision of nutrients, the delivered TMR might be different from the diet formulated by the nutritionist, with the risk of unfulfilling animals’ requirement. The sensor performed a real-time measurement of silages DM content during their loading in the mixer wagon and suggested a correction of their inclusion rate. Our hypothesis was that, adjusting the silages as fed inclusion rate according to the real DM content, the final TMR delivered to the animals would have been closer to the target diet. The employment of the sensor reduced the error in silages DM content loads, however the final TMR was not closer to the formulated diet compared to the TMR conventionally prepared. The lack of result was attributed to errors in the loading of dry feedstuffs (concentrates), which can equally affect TMR composition. Our results thus highlight the necessity of systems to improve the accuracy of TMR preparation. The third study was dedicated to the evaluation of the effectiveness of pomegranate rinds and green tea leaves extract on broiler chicken health and performances. We assessed the potential of the product to improve blood antiradical activity, as a way to increase animals’ defence against oxidative stress. We further investigated the effect on cecal microbiota, observing a positive modulation of beneficial bacterial population, such as Lactobacillaceae. Despite the positive results observed for health-related parameters, growth performances were not enhanced. Lastly, in the fourth study we investigated the effect of nucleotides supplementation to weaning piglets. Nucleotides play a fundamental role in the development of gastrointestinal mucosa and immune system, but due to the high demand in critical moments (i.e. weaning) and the reduced de novo synthesis, their supplementation might be beneficial for the animals. However, we did not observe positive effect of nucleotides supplementation on animals’ immune response, probably due to the optimal conditions where the animals were raised, which minimized the stress usually associated with weaning. Overall, these results contributed to the investigation of technological and nutritional approaches to improve the efficiency of animal feeding. However, further investigations are required to deepen our knowledge about the limitations that have been observed.

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% 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. Sixtysix percent of farmers stated that they were more tolerant of predators since obtaining a LSGD, and 51% 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.