No description available.

No description available.

Local anaesthetic administered epidurally at the base of the tail, and infiltrated into the testes, spermatic cords and neck of the scrotum eliminated the behavioural and plasma cortisol responses associated with castration and tail-docking, confirming that the pain observed was dependent on afferent activity from the affected areas. Having established the neural basis of the responses seen, attempts were made to modify the intensity of pain experienced so that measurement of the changes in behaviour and plasma cortisol concentration could be used to determine the usefulness of the behavioural and physiological indices adopted for the recognition and assessment of pain. Pretreatment with intravenous naloxone 0.2mg/kg I/V), which was anticipated to antagonise an endogenous opioid antinociceptive system activated following castration and tail-docking, provided limited evidence for an increase in pain intensity. 6 procedures which were proposed to represent a range of intensities and duration of noxious stimulation based on the amount and type of tissue involved were ranked in the expected order using the physiological and behavioural indices selected. A study was undertaken to determine if morphine (16mg) etorphine (10nmol) or xylaziantne (50g) by either the epidural or intrathecal route could provide a method by which pain intensity could be reduced in a dose dependent manner, to further improve the indices used for recognising and assessing pain. The results of these studies suggested that the pain produced by castration or castration and tail-docking cannot be eliminated by the doses of the drugs tested and the routes used. To confirm these results preliminary experiments were performed, morphine or xylazine was administered intrathecally to demonstrate active drug gained access to, and had the expected effect on the Sural-semitendinosus reflex in the lamb. Morphine failed to suppress the semitendinosus reflex which is consistent with the results obtained. The suppression of the semitendinosus reflex by xylazine is not consistent with the absence of analgesia in lambs to which either epidural or intrathecal xylazine (50g) had been administered prior to castration or castration and tail-docking, as the general view is that reflex suppression is highly correlated with the level of analgesia. The results of this study present data which shows physiological and behavioural indices can be used to recognise and assess a range of pain intensities in this age of lamb originating from the scrotum, testes and tail.

No description available.

The objective of this research was to investigate the relationship between ante mortem assessments of disease severity and the gross pathological manifestations of disease observed during necropsy. Many clinical assessments are subjective, the hypothesis under investigation is that these correlate with the pathological progression of the disease in the animal. Bronchopneumonia due to Pasteurella haemolytica A1 in calves, Actinobacillus pleuropneumoniae infection in pigs, and Mycoplasma gallisepticum infection of chickens were investigated. The diseases were induced by experimental infection and animals were closely monitored. Both graphical and statistical methods were used to correlate ante mortem measures of disease severity with each other and with post mortem measures of gross pathological lesions and bacteriological isolation of the infecting organism. Calves showed highly correlated relationship between ante mortem and post mortem indicators of disease severity. For pigs, the relationship between clinical variables and gross pathology was much less clear and varied between the three serotypes of Actinobacillus pleuropneumoniae used (serotypes 3, 5a, 9). In chickens, there were few clinical signs evident until the pathology compromised the physiological reserve capacity of the airsacs. Beyond this "threshold", rapid increases in respiratory auscultation score, mycoplasma isolation and serological response were all indicators of increasing gross pathological changes. The relationships between ante mortem assessments of disease severity and the gross pathological lesions recorded at necropsy were usually non-linear and differed for each pair of variables correlated. The relationships between clinical variables being used as indicators of disease severity and the post mortem pathological measures need to be clearly understood for each variable before conclusions concerning the disease severity, prognosis or, in treated animals, efficacy predictions can be made.

A novel thermolysin digestion method for the molecular strain-typing of ruminant TSEs has been developed which resulted in the clearance of cellular prion protein (PrPc) from healthy sheep or cattle brain homogenates, while digestion of scrapie or BSE infected samples resulted in the generation of the full-length disease-related isoform, PrPSc. Using antibodies against the amino terminal region of PrP it was possible to distinguish ovine scrapie from ovine BSE, permitting the potential identification of BSE infected sheep within the UK flock. The identification of a disease-associated, endogenously-generated fragment of PrP (termed C2) in scrapie infected sheep is also described. Absent in healthy brain homogenates, the neuroanatomical distribution of both C2 fragments and thermolysin-resistant PrPSc permitted the classification of four groups within a sample of natural scrapie cases which may be representative of scrapie strain heterogeneity in the UK. The retention of ovine scrapie and bovine BSE prion protein during incubation with six UK lowland soils in soil-packed columns over a period of 18 months was also monitored. Data was collected on the persistence, the vertical migration, and the distribution of PrPSc in soil component fractions. PrPSc bound to all six soils, with elution being dependent on soil type. The majority of PrPSc bound irreversibly, and no migration of PrPSc was observed. Differences in PrPSc persistence were dependent on soil type and prion strain. PrPSc persistence on a single soil at defined pH, temperature, or moisture contents indicated the initial deposition of PrPSc within the column was dependent on soil pH and persistence was inversely correlated to temperature. Reduced soil moisture content resulted in increased elution and persistence of PrPSc. Data suggests that the interaction of PrPSc with soil is a complex phenomenon dependent not only upon soil type and TSE strain but also environmental factors such as soil temperature, pH, and moisture content.

No description available.

No description available.

This thesis has examined the Bovine Spongiform Encephalopathy (BSE) controversy in Korea in terms of civic epistemology conceptualised by Jasanoff. The Korean BSE controversy occurred as a result of uncertainty over BSE being mobilised within complex political and economic contexts between Korea and the US, particularly over the issue of the import of US beef after 2003. The complexity of the interests impeded the Korean government from adopting a clear position on BSE risk in beef, and thus led to public distrust and massive public protests in 2008. The controversy demonstrated what I have called an authoritarian character of civic epistemology in Korea, such as the dominance of the government in knowledge production, public accountability limited to procedural form, and dependence on foreign authority. It can be ascribed to the traces of the development process which had been led by a powerful state and which relied on importing advanced countries’ knowledge and skills. However, simultaneously, the controversy showed that this civic epistemology is in transition, challenged by a growing civil society and an increasing demand for public participation. In light of this, rather than a one-off phenomenon, the BSE controversy in Korea could be defined as a symptom of tension caused by friction between the ingrained approach to policy-making and increasing public awareness of democracy. This pattern of civic epistemology, I suggest, is a distinctive outcome of Korea’s status as a latecomer country which has achieved compressed economic growth and recent political democratisation.

Mycoplasmas in pneumonias of sheep were investigated by survey and by pathogenicity experiments in specific pathogen free (SPF) and conventionally reared lambs. Glycolytic mycoplasmas isolated from sheep in Scotland were found, by comparison with the Queensland Y98 strain, using biochemical and serological tests, to be classifiable as Mycoplasma ovipneumoniae. Two serological tests indicated considerable intraspecific differences among strains. The ultrastructural morphology of M. ovivneumoniae was found to be typical of mycoplasmas. M. ovineumoniae and Mycoplasma arginini were the most commonly recovered mycoplasmas in a survey of housed sheep. Ureaplasmas, hitherto not reported to occur in the ovine respiratory tract, were also isolated. M. ovipneumoniae was recovered from the lungs of most lambs necropsied: its presence with P teurell & haemolvtica was consistently associated with proliferative exudative (P.E.) pneumonia, the incidence of which increased with age. M. arginini recoveries were not correlated with any specific hiatopathological changes. Endobronchiai inoculation with M. ovipneumoniae induced lung changes in only a proportion of SPF lambs, although the lungs of almost all animals became colonised. Lesions were similar to, but milder than, respiratory mycoplasmosea of other species of animals. In-contact transmission produced nasal but not pulmonary infection, and no lung lesions. Attempts to enhance the pathogenic effects of M. ovipneumoniae by sensitization through prior infection were unsuccessful. Endobronchial inoculation of SPF lambs with M. arginini produced neither lung colonisation nor lesions, although the upper respiratory tract became infected. The effects of endobronchial administration of lung homogenates, which were prepared from naturally-occurring P.E. pneumonia and which contained principally M. ovipneumoniae and P. haemolvtica were simulated by mixed cloned cultures of M. ovipneumoniae, M. arginini and P. haemolytica administered to conventionally reared sheep by the same route. Clinical signs and P.E. pneumonia were produced in almost all animals. M. ovipneumoniae was the only consistently recovered organism. P. haemolytica did not establish in the lungs of sheep unless combined with M. ovipneumoniae. This combination produced lesions of P.E. pneumonia. However, P.E. pneumonia was also observed in some animals inoculated with M. ovipneumoniae alone.