No description available.

This thesis uses an interdisciplinary methodological approach including art practice, ethnography and autoethnography as a way of examining the relationship between a farming family and their upland sheep farm in mid- Wales. It draws on the ethnographic methods of 'participant observation' and 'fieldwork' and the translative and transformative potential of artistic practice as means of exploring the working lives and culture of my research participants. My research enquires into the potential of interdisciplinary practice as a useful tool for investigating and giving time/space and voice to the lay discourses of my rural participants. The research participants are also my immediate family members: there is therefore an autobiographical element to this project. To what extent does an 'insider' status allow for a more complex or distinct type of engagement with the lives of my research participants. The thesis includes three practical experiments and three reflective chapters. It is important to note that each chapter and practical experiment has been guided by the fieldwork, and as a result, the chapters are distinct and different in approach and content from one another. The constant in each experiment is connection to the fieldwork. It might be useful to note that there is some overlap between Chapter 3/Experiment 3 and some of the other experiments and chapters of the thesis. Chapter 1 and Experiment 1 focus on place and its importance within my research participants lives; drawing on the critical work of Tim Ingold (2000), Doreen Massey (1999, 2005) and Yi Fu Tuan (1974, 1977, 1996) amongst others. Chapter 2 and Experiment 2 consider contemporary archaeology in relation to the farm; concentrating on the remains of agricultural labour and an acknowledgement that the past and the present intermingle on a daily basis. This chapter draws on the work of Tim Edensor (2005), Henry Lefebvre (2004) and scholars writing from the field of contemporary archaeology. Chapter 3 looks specifically at the relationship between the research participants and their flock of Welsh Mountain sheep, paying particular attention to the curation of both human and animal bloodlines. This chapter draws on the work of Donna Haraway (2008), M.L Ryder (1964, 1983), Sarah Franklin (2007), and Rhoda Wilkie (2010). The thesis includes two photographic books. One evidences the fieldwork and contains specifically chosen photographs from my documentation and their corresponding fieldwork notes. When referring in the body of the thesis to the fieldwork photo-book, it will be numbered as Book 1. The second photographic book contains documentation of the artistic practice including photographic images and 3 DVDs. When referring to this book in the body of the thesis, it will be numbered as Book 2. The thesis seeks to explore the lay discourses of my farming participants; drawing on their expertise and knowledge 'in the field'; the 'everydayness', the ordinary and the mundane are all of importance here; it is through these, I contend, that we are able to understand who we are in relation to our place in the world.

Methane production by ruminants is a significant contributor to agricultural greenhouse gas emissions (Webb et al., 2013). However, current values used to estimate methane output by sheep are default values and do not take into account animal and dietary factors that may affect methane output (Bernstein et al., 2007). Strategies to reduce ruminant methane output are the focus of a large body of research (Iqbal et al., 2008) and, in order to implement these strategies fully, a greater understanding of factors that influence ruminant methane emissions is necessary. The "gold standard" method for measuring methane output by sheep is the use of respiratory chambers (Blaxter and Clapperton, 1965). However, this method is expensive, time-consuming and labour intensive, making it unsuitable for use in an on-farm situation. The work presented in this thesis explores the potential of three proxies to estimate methane output by sheep, which could be used or adapted to be used as a practical means of estimating methane emissions from sheep on a large scale. The proxies investigated here are a Laser Methane Detector (LMD), used to take measurements of methane concentration from air expired by sheep, in vitro gas production analysis of feeds offered to sheep, and Fourier-transform infrared spectroscopy (FTIR) analysis of feeds offered to sheep. Predictions of methane output obtained from each of the proxies are validated using respiratory chamber measurements taken from sheep offered a variety of feeds during different experiments. With further development and validation, all three proxies presented in this thesis demonstrate potential to be used to successfully estimate or predict methane output by sheep as measured in respiratory chambers.

No description available.

A program of study was undertaken to asses the effect of pre-weaning feeding behaviour on post-weaning feeding behaviour in pigs weaned at various ages (3, 4 and 5 weeks of age) and to identify ways of increasing their post-weaning feed intake. The studies were constructed using time extensive continuous recording methods in order to monitor the 'true' behaviour unbiased by sampling errors. Piglets weaned at 3 weeks of age had the ability to grow faster and became significantly heavier at six weeks of age (3W: 12.S06 ± 0.629 kg) than piglets that had to extent their stay for one (4W: 10.S14 ± 0.693 kg) or two more weeks (SW: 10.987 ± 0.376 kg) with the sow. In addition, 4W piglets had the greatest difficulty adapting to their new environment in comparison to 3W and SW piglets, as they had greater scores on aggressive and abnormal behaviour during the week post-weaning. This study demonstrated that the provision of a familiar feeder post-weaning i) allowed all 4W piglets, irrespective of their pre-weaning feeding experiences, to allocate the feeding resources unaided and autonomously without having to rely on the feeding temperament of their more experienced littermates or having to imitate them eating, ii) helped the less experienced piglets of the litter (regarding their feeding behaviour) to build a stronger immune system and to become heavier at the end of the first week and iii) improved the welfare of the piglets soon after weaning as they were performing significantly less belly-nosing in contrast to equivalent piglets that were not suited with a familiar feeder. Also, extensive pre-weaning feeding behaviour can help 4W piglets obtain a stronger immune system by the end of lactation independent of their weight and their teat order. The study reported in this thesis provides good evidence that choosing to use a time-period which was previously applied by other researchers could lead most of the times to incorrect conclusions. Also, short time-sampling strategies have been proven to be insufficient to provide strong or valid statistical associations with the 'true' duration of the behaviours under investigation (r<70%). Continuous weekly recordings during the day hours (8:00 to 17:00h) were shown to be sufficient to provide measurements of strong association with the 'true' duration of the behaviours for the given week.

The knowledge of iron biogeochemistry is constrained by paucity in the understanding of its uptake, transport and the partitioning of the element between different phases, redox states and coordination sites. The work presented in this thesis describes the optimisation and evaluation of a Flow Injection Chemiluminescence (FICL) method for the shipboard determination of dissolved Fe(II) species (< 0.2 µm) in seawater. This includes results from two ship-board trials and a study of the effects of model ligands on iron redox speciation measurements in natural waters. The method was also used to determine the distribution of dissolved iron species (< 0.2 µm) in two contrasting study areas in the North East Atlantic Ocean and for a study of aerosol iron dissolution in seawater. The FI-CL method was evaluated and was found to be robust and sensitive, to have low limits o f detection (5-12 pM) and short analysis times 3 min) suitable for the high resolution spatial and temporal sampling required for shipboard analysis of Fe(II). A study of the effects of model ligands on Fe(II) determination revealed no conclusive evidence for significant interference from organic molecules on the method but Fe(III) in the presence of certain organic molecules had the potential to cause positive and negative interference in aqueous samples. Field survey results obtained for a transect between the Bay of Biscay to the coast of the Netherlands, showed enrichment of dissolved iron (0.7 - 2 nM) on the European continental shelf in March 2002. Near the shelf break, the iron enriched shelf waters were separated from low iron open ocean surface waters (0.15 - 0.4 nM) by a well-defined mixing gradient. Elevated dissolved Fe(II) concentrations (> 100 pM) were observed at the shelf break and during a solar radiation maximum in the coastal waters of the southern North Sea. These features were attributed to the dissolution of Fe(II) from anoxic sediments and photoreduction of iron from dissolved and suspended particles, respectively. hi the surface waters of the Canary Basin in October 2002, low Fe(II) concentrations that varied from below the limit of detection of the FI-CL method (< 5 pM) to 60 pM were determined. A horizontal dissolved iron gradient (0.1 - 1.0 nM) inversely related to distance from the North West African coast was observed. It was hypothesised that the gradient was caused by the advection of enriched coastal and upwelled water, rather than by spatial variation in aerosol deposition. Preliminary aerosol iron dissolution experiments demonstrated the significance of the effect of dust loading and variation in seawater matrix on iron solubility. In conclusion, continental margins were found to be a highly significant source of dFe in both study areas and evidence was found that a major portion comes from the reductive dissolution of iron in sediments. However, the flux of iron from shelf waters to the open ocean is likely to be dependant on several factors, such as the direction and magnitude of lateral and axial advection and the efficiency of scavenging and biological uptake in the surface waters.

No description available.

No description available.

No description available.

Contagious ovine digital dermatitis (CODD) is a cause of severe lameness in sheep in the UK. The aim of this study was to gain a greater understanding of this disease and provide practical information for application on farms. A cross-sectional postal survey of 511 farmers in Wales provided information on prevalence, geographical distribution and farmer reported risk factors. CODD was shown to be now endemic in the UK with 35% of farms affected, and an average on farm prevalence of 2.0% although some farms experienced a much greater prevalence. Larger farms were reportedly more at risk, as were those with bovine digital dermatitis (BDD) in their cattle. There has been a rapid increase in reports of CODD arriving on farms since 2000, and farmers considered concurrent footrot, buying in sheep, adult sheep, time of year and housing to be associated with CODD. A four-point ordinal locomotion scoring tool was developed enabling farmers and veterinarians to score the severity of a locomotion abnormality in sheep. This had high levels of intra-observer repeatability: weighted kappa (κW) 0.81 for veterinarians and 0.83 for farmers. A detailed clinical description and five-point lesion grading system were developed in order to aid diagnosis amongst veterinarians and farmers, and to aid communication. Radiographs also highlighted the extensive damage to soft tissues and bony structures that may occur in advanced clinical cases, and locomotion scoring demonstrated a variation in welfare impact by lesion grade. Histopathology provided detailed evidence of the pathological processes occurring in clinical lesions. Early lesions were characterised by a lymphoplasmacytic infiltrate of the distal digital skin, with suppurative coronitis and intracorneal pustules. In more advanced lesions there was complete separation of the dorsal hoof wall with a necrotizing and fibrinosuppurative exudate and dermatitis. Later lesions were mostly resolved, but with milder suppurative changes remaining within the cornified layer and periosteal reaction of the dorsal aspect of the distal phalanx. Immunohistochemistry revealed large numbers of treponemal-like organisms particularly within early lesion grades specifically associated with the histopathological changes. A longitudinal repeated cross-sectional field study of six farms with CODD over 16 months provided information on risk factors for CODD. Footrot was strongly associated with CODD at foot level OR: 7.7 (95%CI: 3.9-15.5), as were various pasture based factors. There was a temporal variation in the prevalence of CODD with increases observed in early Autumn and after housing. The minimum inhibitory/minimum bactericidal concentrations (MIC/MBC) of twenty CODD associated Treponema. spp isolates to ten antimicrobials were determined using a microdilution method, with penicillins and macrolides demonstrating the lowest MIC/MBC values. A cluster randomised controlled trial of 24 farms with CODD, using whole flock systemic metaphylactic tilmicosin, together with repeated treatment and isolation of clinical cases failed to eliminate CODD and footrot. The high failure rate (7/13 farms) was considered to be as a result of biosecurity breaches and one control farm managed to eliminate CODD without the whole flock approach.