Bovine mastitis is recognised worldwide as the most important and costly disease affecting dairy cattle. The reduction of herd mastitis rates is crucially needed to improve animal welfare and profitability, and lessen the reliance on antibiotics. Single nucleotide polymorphisms (SNPs) within genes that have a critical role in the innate immune response, such as Toll-like receptors (TLRs) and the chemokine receptors CXCR1 and CXCR2, could impact on establishment and progression of intramammary infection, and therefore influence an animal’s susceptibility to disease. The genetic selection of animals with favourable TLR and CXCR1/2 mutations, with no impact on production traits, could be incorporated into dairy breeding programmes. In order to investigate any associations with clinical mastitis (CM) incidence and milk quality and quantity, this study identified and analysed SNPs alongside actual CM and production data from a Holstein-Friesian herd. This revealed 46 SNPs, 9 of which are novel, within boTLR1/4/5, boCD14, boCXCR1 and boCXCR2; selected SNPs were then tested for association with CM. This is the first report of boTLR1 SNPs and a non-coding boCXCR1 SNP that associate significantly with susceptibility to CM. Favourable linkage of reduced CM with increased milk fat and protein was observed, indicating selection for these markers would not be detrimental to milk quality. Furthermore, this study provides evidence that some of these SNPs underpin functional variation in bovine TLR1 and CXCR1, and possibly underlie an immunological mechanism for disease susceptibility. SNPs in boTLR1 and boCXCR1 were significantly associated with impaired transcript levels in milk somatic cells. In addition boTLR1 SNPs associated with impaired cytokine responses from cell populations when exposed to ligand or heat-killed mastitis-causing bacteria. The potential impact of boTLR1 variation on the immune response to Staphylococcus aureus is demonstrated, and this has implications for boTLR1-mediated immune responses to other pathogens.

As the global population increases, estimated to reach 9 billion by the year 2050, global food security becomes a priority. A prominent disease implicated in financial loss to the poultry industry, on a global scale, is infectious bursal disease virus (IBDV). Vaccination against IBDV is sub-optimal and difficult to deliver. Therefore it has been highlighted as a key area for the development of an oral vaccine. A highly conserved capsid protein from IBDV (VP2) was identified, and sub-cloned into a bacterial expression cassette. This protein was fused to a potential carrier protein (cholera toxin B chain), previously shown to mediate the exit from the gut lumen into the lamina propria. However, to allow this antigen to reach the mucosal associated lymphoid tissue, the protein antigen must remain in its native conformation through the stomach. This work developed a delivery system to meet this end. By encapsulation within a fatty acid coated, protein adsorbed-solid core drug delivery system (SCDDS), it was shown that a model protein antigen (GST-GFP) could be protected from low pH (i.e. pH 2.0) and proteases. Protease protection was demonstrated against the exposure of myristic acid coated, GST-GFP adsorbed silica, to both protease K (100 μU, 1hour (100% protection)) as well as a simulated in vitro stomach environment (pepsin (0.2 mg) (100% protection)). Having demonstrated protection from proteases at pH 2.0 and pH7.4, it was then shown that GST-GFP could be released from the myristic acid coated silica at pH 8.8 (consistent with the small intestine). As much as ~15% (15 μg) (w/w) GST-GFP was released from the aforementioned system. The evidence supporting this conclusion was drawn from molar ellipticity calculations that showed the proportion of helical structure in relation to regions of beta sheet remained constant, pre-adsorption and post-release (16.9% α-helix, 20.8% β-sheet, 43.3% random coil). Finally, this work has shown that if a recombinant antigen was fused to cholera toxin B chain (but not shiga toxin B chain), it was capable of mediating transcytotic passage across, differentiated, polarised Caco-2 cells (1/1000th input (10 ng)). In conclusion and based upon the evidence provided above, this system warrants further optimisation and investigation to serve as an oral vaccine delivery system to treat IBDV.

This thesis investigates how hydrocolloids can be incorporated into pet food meat products to provide novel applications. The possible applications that have been investigated for hydrocolloids are satiety and the production of more sustainable meat products. The research was carried out to improve canned pet food and the processes used to manufacture the product. The main section of the thesis looks at incorporating alginate and pectin solution into a food product which then becomes a gel in a low pH environment. The gel produced in the stomach should produce a satiety effect within the pet. Hydrocolloids used in other studies have been shown to induce satiety in humans. The gel was tested in vitro with a positive result which showed good gelation; however, when tested in vivo, no reduction in food intake was seen. These results may indicate that satiety has different trigger mechanisms in dogs compared to humans. More research is needed to understand whether dogs have the same hormonal responses to satiety as humans. The second application was the use of agar and methylcellulose (MC) to produce a thermally stable gel. The incorporation of this gel structure into a wet meat product would allow the level of meat to be reduced and additional powders to be used as a nutrient component instead. A thermally stable gel also enables the pet food to be processed more efficiently. The gel allows the meat chunks to be cut at high temperatures; therefore, no cooling step is needed in production. Agar and MC produce a strong thermally stable gel at both high and low temperatures. There is evidence that an interpenetrating network is formed in which the molecular ordering and aggregation of the individual polymers appears to be affected by the presence of the second polymer. The use of hydrocolloids for new applications in meat will transform and improve the quality of these products in the future.

Mastitis remains one of the most common, costly and intractable diseases affecting the dairy cattle industry worldwide. In spite of concerted efforts meaningful progress in reducing the incidence of mastitis has been limited over the past thirty years by our partial understanding of the epidemiology of key pathogens, such as S.uberis. The aim of this thesis was to investigate the epidemiology of S.uberis mastitis by analysis of the population structure and transmission dynamics of clinical mastitis patterns within and between commercial dairy herds in England and Wales. In Chapter 3 Multi Locus Sequence Typing (MLST) was used to describe the sub-species (sequence type) genetic heterogeneity of S.uberis isolates collected from a longitudinal study of clinical mastitis on 52 farms. The clinical cases were classified according the pattern of occurrence of the sequence types in the herds. The findings suggested that a small subset of MLST sequence types were disproportionally important in the epidemiology of S.uberis mastitis, with cow-to-cow transmission of S.uberis, potentially occurring in the majority of herds in the United Kingdom; this may be the most important route of S.uberis transmission in approximately one third of herds. In Chapter 4 cow and herd level variables, including monthly recorded milk constituents, yield and parity were evaluated against the clinical case classifications defined in Chapter 3. The temporal relationships between clinical cases and classifications were also evaluated as potential predictors of transmission dynamics within a herd. The findings indicated that the time interval between clinical cases classified by genotype as potentially contagious transmission was significantly shorter than that between successive mastitis clinical cases attributed to environmental transmission. The distribution of clinical cases throughout lactation also indicated a higher proportion of potentially contagious isolates were cultured from clinical cases originating from lactation rather than the dry period compared to those attributed to environmental transmission. In Chapter 5 Matrix Assisted Laser Desorption (MALDI) mass spectroscopy was used to generate spectral profiles of S.uberis isolates cellular composition. Spectral profiles were used successfully as an alternative method of discriminating between clinical mastitis isolates associated with contagious transmission from those associated with and environmental origin of infection defined in Chapter 3. The findings of this chapter demonstrated marked variation between herds in the spectral profiles of isolates from the same clinical case classification. In Chapter 6 selected isolates of S.uberis associated with contagious transmission and persistent intramammary infections were sequenced using next generation technology and compared by core genome multi locus sequence typing (cgMLST) to evaluate the discriminatory capacity of the MLST and MALDI. The results from this chapter confirmed the importance of the herd unit in the genotypic population structure of S.uberis suggested by the results of Chapter 5 and also support the results of Chapter3 which suggest ‘low grade’ contagious transmission of S.uberis is superimposed on a ubiquitous, environmental S.uberis mastitis pattern in many herds This thesis demonstrated that the S.uberis population is complex with variation at the bacterial, cow and herd level suggesting different patterns of disease and bacterial evolution occurring in different circumstances. Categorisation of sub-species of S.uberis within herds as being transmitted via contagious or environmental routes appears to be eminently achievable using modern, high throughput technologies; this could lead to a step change in mastitis control.

Contemporary reports showing negative temporal trends in human sperm quality have provided a weight of evidence, in spite of recognised methodological weaknesses of the early research, strongly indicative of declining male fertility over the past six decades. Other aspects of human male reproductive development, such as hypospadias, cryptorchidism and testis cancer are also showing negative trends in incidence and geographic variation in prevalence. Together these negative changes in parameters of fertility, which have comorbidity, are termed Testicular Dysgenesis Syndrome (TDS). The relative short time period of the trend data and the spatial heterogeneity of these factors suggest an environmental aetiology. Two neighboring and ethno-linguistic similar countries, Denmark and Finland, are used as evidence of this as Denmark has significantly decreased sperm quality as well as an increased incidence of other aspects of TDS when compared to neighboring Finland. Additionally, exposure to persistent environmental chemical pollutants has been associated with decreased sperm quality and increases in other components of TDS. The suggested underlying cause of TDS is perturbed foetal/embryonal programming and reproductive development. In spite of overall poor epidemiological information and a paucity of empirical research data from companion animals there are suggestions that environmental pollutants are affecting the health of cats and dogs. Indeed, the dog may be a relevant research model as it shares our environment and ill health associated with it, such as human TDS. Based on the evidence of environmental pollutants affecting human and animal reproductive development and fertility, this PhD project was developed in order to determine if man’s closest companion, and the animal which wholly shares our environment, demonstrates any parallel reproductive impairment. Specifically, this thesis aims to investigate negative temporal trends related to canine fertility, determine the presence of and geographic variation in tissue concentrations of exemplar environmental pollutants and examine testes tissue and sperm cells, via culture and histology, for association between chemical concentrations and quantitative assessments. Canine testes were collected from three countries; UK (n = 58), Finland (Helsinki region) (n = 20), Denmark (Copenhagen region) (n = 10). These samples were tested for concentrations of three representative chemical groups: PCBs, PBDEs, DEHP. Samples of commercial dog food (n = 28), and a range of canine body fluid was also analysed for these same chemical groups. A retrospective analysis of database information from a population of service dogs in the UK was used to determine temporal trends in canine sperm quality and cryptorchidism over a 26 year period. The concentrations of the three chemical pollutant types were additionally analysed against land use with a Geographic Information System (GIS) and two CORINE land use categories: Artificial and Agricultural. These tissues were assessed histologically using histomorphometric scores, CYP11A1 area stained. Canine testes tissue and sperm were cultured with PCB153 and DEHP to determine direct effects of short term exposures to environmental pollutants by assessing testosterone production (testes explant culture), motility (CASA), sperm viability (hypo osmotic swelling test, chromatin integrity, live:dead ratio). Database analysis of service dog fertility reported two components of TDS: negative temporal trends in sperm quality and a concurrent increased incidence of cryptorchidism. Samples of canine testes tissue contained measurable concentrations of three exemplar pollutants (PCBs, PBDEs, DEHP). These pollutants were also largely present in commercial dog food and some were also present in prostatic fluid, full ejaculate and bitches milk. The profile of EDs and concentrations of specific chemicals showed significant variation across three regions of the UK (Southeast, East Midlands, and West Midlands). Notably, concentrations of legacy industrial chemicals (PCBs, PBDEs) were highest in the West Midlands and phthalate (DEHP) was highest in the southeast. The concentrations of DEHP was significantly higher in Artificial land categories compared to tissue collected in Agricultural land use areas (P < 0.05). Canine testis samples collected from three international regions contained concentrations of PCBs and DEHP which were significantly higher in the UK (P < 0.05) and PBDEs which were significantly higher in Finland (P < 0.05). The histomorphometric assessment of testes showed significant variations across the three countries. The quantification of immunohistochemical testis area stained for CYP11A1 from the three countries showed a significant variation (P=0.0001), and tissue from Denmark showed a significant association between area stained and concentrations of DEHP (P < 0.05). Tissue exposed, via testes explant culture, to PCB153 and DEHP at two concentrations showed no significant blunting of LH stimulated testosterone secretion. Sperm exposed, via culturing with two environmentally relevant concentrations of PCB153 and DEHP, exhibited significantly increased (P < 0.05) and decreased (P < 0.05) measures of motility with these chemicals respectively. Additionally sperm viability, measured using the hypo osmotic swelling assay, was significantly reduced in the presence of PCB153 (P < 0.05) and a significant increased when cultured with DEHP (P < 0.01). Both chemicals significantly increased sperm DNA fragmentation. Additionally, short term exposure to both chemicals significantly reduced the Live:Dead ratio of sperm (P < 0.05). Robust, determinative evidence of negative trends in canine sperm quality and incidence of cryptorchidism indicate that canine and human male fertility are decreasing in parallel. An environmental aetiology is supported by the presence of environmental chemicals in canine diet, testes tissue, prostatic fluid and full canine ejaculate. Geographic differences (National and International) in testis chemical profiles and concentrations may equate with reported regional differences in human TDS. In support of this hypothesis, specific canine testis chemical concentrations were associated with histomorphometric scores from the same cohort of samples. Direct effects of PCB153 and DEHP on sperm motility and viability may be indicative of an alternative acute negative effect on male fertility. These data suggest that the dog, while living in a shared environment with humans, exhibits some parameters of TDS and that canine, as well human, male fertility is declining due to exposure to environmental chemicals.

Using a Bourdieuian approach, the main argument of this thesis is that men and women develop an embodied racing habitus that is shaped by their access to economic, social, cultural and physical capitals. This determines how much power, influence and recognition they enjoy, and positions them differently within the class and gender hierarchy of the racing field. The thesis begins with a historical and contemporary analysis of the racing field and apprenticeships as a model of learning, showing how power was held in the hands of the Jockey Club, once the sole ruling body of racing, from the mid 18th century. It governed the racing field through class privilege and through its members having access to certain forms of economic, social and cultural capital. The entry of women into the racing field began in the 1960s when women with suitable economic and cultural capital gained the right to train as racehorse trainers. Working-class men were already part of the employment hierarchy, as indentured apprentices, and it was due, in part, to a shortage of small 'boys' that working-class women were taken on as stable 'lads' or 'girls'. The equalities legislation of the 1970s meant women could be members of racing's workforce as well as gaining the right to hold jockey's licences. The process of learning to become a stable 'lad' takes place 'on the job', through practice; this means that women become accepted as workers as long as they act 'like one of the lads' and embody a certain form of masculinity. Indentured apprenticeship was abolished in 1976 and replaced by a system of modern apprenticeship. This has gone along with a change in the significance of physical capital, an increase in the division of labour, and an increased reliance on migrant workers.

Streptococcus uberis is a Gram-positive, catalase-negative member of the family Streptococcaceae and is an important environmental pathogen primarily responsible for a significant amount of bovine intramammary infections. This thesis describes the sequencing and comparison of multiple strains from clinical and sub-clinical infections. Following de novo assembly, these are compared to the single reference strain (0140J). The assemblies of strains sequenced with two technologies (Illumina and SOLiD) were compared. From these assemblies, annotation allowed the comparison of gene content, the pan and core genomes and gene gain/loss of coding sequences associated with clustered regularly interspaced short palindromic repeats (CRISPRs), prophage and bacteriocin production. Identification of sequence variants allowed identification of highly conserved and highly variant genes. Inferred intraspecies and interspecies (host-S. uberis) protein-protein interaction networks revealed pathways of bovine proteins enriched with potentially interacting pathogen proteins. These identified known and predicted pathways and also novel interaction partners. This was the first “whole-genome” comparison of multiple S. uberis strains isolated from clinical vs non-clinical intramammary infections including the type virulent vs non-virulent strains. These data allowed the first insight into potential evolutionary forces behind virulence differences.

Over the last three decades, there has been increasing concern over environmental effects on human male reproductive health. Both temporal and regional trends in semen quality, testicular cancer and malformations at birth have been associated with changes or differences in exposure to chemicals present within the environment. These abnormalities are typically classified under one entity, Testicular Dysgenesis Syndrome [TDS]. Since temporal trends in sperm quality have also been reported in the dog, it was proposed that this may reflect a common cross-species environmental aetiology and that the dog is a sentinel for human exposure to ECs. The overarching hypothesis of this thesis is that the dog may exhibit regional differences symptomatic of TDS and may respond to environmental influences in a similar manner to the human. Experimental studies designed to test this hypothesis focused on (1) the sensitivity of sperm to environmental influences, (2) canine sentinel testicular chemical profiles and pathological features of testes from specific geographical regions and (3) possible environmental influences impacting on cryptorchidism in dogs. Humans and animals are not directly exposed to single chemicals but to a mixture of environmental toxicants present within the environment. Chapter 3 initiated investigations into mixture effects of ECs by utilising a novel full factorial chemical model of two chemicals known to be present in reproductive tissues. Concentrations of di (2-ethylhexyl) phthalate [DEHP] and polychlorinated biphenyl congener 153 [PCB-153] at environmentally relevant levels, as determined by testicular chemical profiling of dog testes, and their effects upon parameters of sperm quality, were tested in vitro. While subtle differences in motility were observed between species, DNA fragmentation was increased similarly in both the human and dog following EC exposure. Although this applied to individual and mixed chemicals, the effects of one chemical impacted on the activity of the other dependent on the concentration ratio. Interestingly, for DNA fragmentation, data presented suggests that PCB-153 is the driver behind increased sperm DNA damage in both species. Since the data alluded to above support the concept of utilising the domestic dog as a sentinel for human exposure to ECs, the dog was used to investigate regional variation upon testicular developmental, morphological and histopathological features. The regions selected for in this component of the thesis display different degrees of industrialisation and thus variation in exposure to environmental contaminants. Data presented demonstrate significant regional variation in chemical profiles, testicular developmental markers and histopathological features indicative of TDS. Specifically, testicular DEHP and PCB-153 with known geographical variation, were found to be positively associated with markers of proliferation and spermatogenesis. Interestingly, a further chemical present in dog testis, poly-brominated diphenyl ether congener 47 [PBDE-47], was negatively correlated with these markers. Furthermore, a novel system developed to assess and score histopathological abnormalities in testes, revealed a higher range of atypical features in testes from the UK compared to those collected from Scandinavia. A further novel element of this thesis was the development of a survey to assess environmental influences on cryptorchidism across several breeds of dog. Uniquely, a higher prevalence of cryptorchidism was observed in deerhounds originating from the East Midlands. Of the range of environmental influences investigated, a key observation was that some bitches of cryptorchid pups were fed a specific brand of feed previously reported to contain ECs. Assessment of further environmental factors covered by the survey such as exposure to pesticides, cigarette smoke and air fresheners provided preliminary information pending the further repeat release of the survey to the same breeders in future years. These data provide preliminary evidence into possible environmental factors that could influence canine and human reproductive health. In conclusion, the results presented in this thesis are significant since they add considerable weight to the paradigm that environmental factors impact directly on male reproductive function. Unique data presented within this thesis emphasises that specific chemical types perturb sperm function and these chemicals vary by region. Furthermore, the work presented here consolidate the suitability of the domestic dog as a sentinel for human exposure to contaminants thus providing the added benefit of enabling access to reproductive tissues from different regions as an index of human reproductive health.

This thesis provides new ways of thinking about human-bird encounters under domestication, providing the first substantive geographical study of ‘pigeon geographies’. It explores the spaces, practices, and human-pigeon relationships involved in pigeon showing and long-distance pigeon racing in Britain, from the mid-nineteenth century up until World War Two. The growth of fancy pigeon exhibitions was part of a wider Victorian passion for domesticating animals, at a time when human bodies were also subject to increasing aesthetic and moral scrutiny. Long-distance pigeon racing emerged at the end of this period, organised competitive sport more generally seen as an important means of moral improvement and identity expression. Like many other competitive pastimes in the second half of the nineteenth century, then, institutional bodies were formed to manage the expansion of showing and long-distance racing. The Pigeon Club and the Marking Conference were formed in 1885 to oversee British pigeon exhibitions, whilst the National Homing Union, formed in 1896, governed British long-distance pigeon racing. Both pastimes facilitated the formation of social worlds around varieties of domestic pigeon (Columba livia) and their respective practices. Whilst these pastimes historically had strong concentrations of male working-class followers – particularly in the north-west and north-east – they were both widespread throughout Britain and spanned all socio-economic classes, although accounts of female fanciers were rare. Through the exhibition of pigeons, fanciers debated and defined aesthetics, formulating breeding standards for each fancy breed, and questioning the ways in which pigeons were manipulated – sometimes contentiously – to produce the ‘ideal’. Long-distance pigeon racers, on the other hand, sought to understand and hone their birds’ athletic abilities, becoming entangled in scientific debate about homing, as well as geographical questions about the conduct and regulation of their sport. Racers were also drawn into aesthetic debates, exhibiting their racing birds during the off-season, the show pen becoming a fascinating frontier between showing and racing. Through the organisation of the spaces and practices that made up the fabric of these pastimes, pigeon showing and long-distance racing reconfigured both humans and their birds, the two becoming closely intertwined through collaborative encounters.

Depression is a heterogeneous condition characterised by low mood and a lack of motivation and enjoyment of regular activities. The response rate to current treatments coupled with adverse side effect profiles requires new avenues of investigation into the development of novel therapeutics to treat the condition. Rearing rats in isolation from weaning causes behavioural, cognitive and neurochemical changes which persist into adulthood; some of the symptoms produced have relevance to depression. In the current thesis, rats raised in social isolation from weaning consistently developed a hyperactive phenotype compared to group-housed littermates when placed into a novel environment. They also developed deficits in associative learning assessed by the conditioned fear response task. They displayed some anxiety-like behaviours in the open field and novelty-suppressed feeding task and deficits in visual memory in the novel object discrimination task, although these were not reliable across cohorts. There was a reduction in levels of hippocampal neurogenesis in a number of cohorts and for the first time it was demonstrated that rats reared in isolation exhibited changes in gut bacteria, opening up a potential new avenue of investigation into potential treatments. The efficacy of novel versus established antidepressant treatments was evaluated in isolated rats. Chronic fluoxetine had some anxiolytic effects in the open field, attenuated isolation induced changes in associative memory and increased neurogenesis but also had inconsistent effects on activity. Treatment with acute ketamine increased freezing time in the conditioned freezing response task, indicating an improvement in associative memory. The final study examined, for the first time, the effect of treatment with the JNK-1 inhibitor DJNKI in isolation reared rats. DJNKI had some positive cognitive effects in both the novel object discrimination task and the conditioned freezing response task. In conclusion, the isolation rearing model induced varying levels of depression-like deficits, which were responsive to some treatments. The model is a useful tool for investigating the symptoms of depression and evaluating novel treatment options.