Trypanosomiasis is one of the most important animal diseases in Ethiopia causing many thousands of deaths each year and the disease is not limited to Ethiopia alone. Approximately quarter of the total land surface of the African continent is estimated to b infested by tsetse flies and virtually allot this infested area 1s south of the Sahara. The geographical distribution of the various species of trypanosomas and their vector host, the tsetse flles. has been studied by a number of investigators. While all the species of the cyclically transmitted trypanosomes are distributed over Africa south of the Sahara, the predominant species vary between east, central, and west Africa.

The aim of this research work was to investigate and quantify the risk of fatal and fracture injury for Thoroughbreds participating in flat racing in the US and Canada so that horses at particular risk can be identified and the risk of fatal injury reduced. Risk factors associated with fatalities and fractures were identified and predictive models for both fatalities and fractures were developed and their performance was evaluated. Our analysis was based on 188,269 Thoroughbreds that raced on 89 racecourses reporting injuries to the Equine Injury Database (EID) in the US and Canada from 1st January 2009 to 31st December 2015. This included 2,493,957 race starts and 4,592,162 exercise starts. The race starts reported to the EID represented the starts for 90.0% of all official Thoroughbred racing events in the United States and Canada during the 7-year observation period. The annual average risk of fatal and fracture equine injuries for the period 2009 - 2015 was estimated and a description of the different injury types that resulted in fatalities and fractures was given, based on the cases recorded in the EID. Possible risk factors were pre-screened using univariable logistic regression models; risk factors with an association indicated by p < 0.20 were then included in a stepwise logistic regression selection process. A forward bidirectional elimination approach using Akaike's Information Criterion was utilised for the stepwise selection. We identified more than 20 risk factors that were found to be significantly associated with fatal injury (p < 0.05) and more than 20 risk factors associated with fracture injury, across the final multi-variable models. The risk factors identified are related to the horse’s previous racing history, the trainer, the race, the horse's expected performance and the horse's racing history. Five different algorithms were used to develop predictive models based on the data available from the period 2009 - 2014 for both fatal and fracture injuries. Firstly, we used Multivariable Logistic Regression, commonly used in risk factor analysis. Secondly, Improved Balanced Random Forests were developed, a machine learning algorithm based on a modification of the random forests algorithm. Because fatal injuries are extremely rare events, less than 2 instances per 1000 starts on average, balanced samples were used to develop the Random Forest model to deal with the class-imbalance problem. Furthermore, we trained an Artificial Neural Network with a single layer and two networks with deep architecture, a Deep Belief Network and a Stacked Denoising Autoencoder. As artificial neural networks and deep learning models have been successfully used to solve complex problems in a diverse field of domains we wanted to explore the possibility of using them to successfully predict equine injuries. The performance of each classifier was evaluated by calculating the Area Under the Receiver Operating Characteristic Curve (AUC), using the data available from 2015 for validation. AUC results ranged from 0.62 to 0.64 for the best performing algorithm and similar predictive results were obtained from the wide array of different models created. This is the first study to make use of the extensive information contained in the EID to identify risk factors associated with equine fatal and fracture injuries in the US and Canada for this period. To our knowledge, this is the largest retrospective observational study investigating the risk of equine fatal and fracture injuries during flat racing in the literature. This is also the first study to train logistic regression and machine learning models to predict equine injuries using such an extensive amount of data and a full year of horse racing events for prediction and evaluation. We believe the results could help identify horses at high risk of (fatal) injury on entering a race and inform the design and implementation of preventive measures aimed at minimising the number of Thoroughbreds sustaining fatal injuries during racing in North America.

Porcine congenital splayleg (PCS) is the most important congenital condition of piglets, associated with lameness and immobility, of unknown aetiology and pathogenesis. The aim of this study is to investigate the cellular and molecular changes in skeletal muscles of PCS, thereby gaining new molecular insights into this clinical condition. Based on immunohistochemistry and histological image analyses on 4 sets of 2-day- old splayleg piglets, each with a corresponding normal litter mate, a consistent discovery has been that PCS muscles [semitendinosus (ST), longissimus dorsi (LD) and gastrocnemius (G)] showed extensive fibre atrophy without apparent tissue damage. At present, it is not certain if PCS-associated fibre atrophy is accompanied by fibre hypoplasia. Both normal and PCS muscle fibres showed similar widespread distribution of lipid- and oxidative-positive fibres. Although there was no significant difference in fibre type composition, several structural myosin heavy chain (MyHC) genes were significantly down-regulated in PCS affected muscles. Interestingly, MAFbx, a major atrophy marker, was highly up-regulated in almost all PCS muscles, when compared with controls from normal litter mates. In contrast, P311, a novel 8- kDa protein, was relatively down-regulated in all PCS muscles examined. To further investigate the functional role of P311 in skeletal muscle, its full-length cDNA was sequenced (Accession. N0. EF416570) and over-expressed in murine C2C12 muscle cells. P311 over-expression enhanced cell proliferation and reduced myotube formation in C2C12 cells. The over-expression of calcineurin, a key intracellular calcium-dependent signalling factor of muscle differentiation, down- regulated P311 expression. Reduced P311 expression in PCS piglets might contribute to atrophy through reduced myotube contribution. To investigate the functional role of SPARCL-1, a matricellular secreted glycoprotein that belongs to SPARC family, its full-length cDNA was sequenced (Accession. N0. EF416571) and over-expressed in murine C2C12 muscle cells. SPARCL-1 overexpression led to reduced cell proliferation and down-regulation of MyHC genes during late differentiation. SPARCL-1 might be associated as a negative regulator of skeletal muscle cell proliferation and cell differentiation. However, endogenous SPARCL-1 expression was similar between PCS and normal muscles. Hence, although SPARCL-1 could play a role in muscle development, it is unlikely to be a main factor in the development of PCS. In summary, PCS is shown to be a condition characterised by extensive fibre atrophy and raised fibre density, and it is proposed that the combined differential expression of MAFbx and P311 is of potential value in the diagnosis of sub-clinical PCS.

Theileria annulata is a protozoan parasite of cattle, that causes the disease tropical theileriosis throughout sub-tropical regions of the Old World. Theileria parasites have the ability to immortalise the host leukocyte they infect causing clonal expansion and dissemination of infected leukocytes throughout the host. This property has allowed the development of an in vitro system for the culture of bovine cells infected by the macroschizont stage of the parasite. In addition, differentiation of the parasite towards the next life cycle stage, the merozoite, can be induced in culture. The signals that cause the macroschizont to differentiate into merozoites are not fully understood, although it is known that this event is associated with a major elevation in merozoite gene expression (Shiels et al., 1994). Recently a small family of parasite genes that are negatively regulated early during differentiation to the merozoite were identified. One member, known as TashAT2 contained predicted AT hook DNA binding motifs and was shown to be localised to the host cell nucleus. It has been postulated that the TashAT2 polypeptide may play a role in the regulation of macroschizont or modulation of host cell gene expression (Swan et al., 1999). The focus of this project was to characterise TashAT1, a second member of the TashAT gene family. To this end, the TashAT1 gene was sub-cloned and sequenced and mapped to a region of the genome containing TashAT2 and a third Task AT gene, TashAT3. The 1.4kb open reading frame of TashAT1 was virtually identical to the five prime end of TashAT3, indicating that TashAT1 or TashAT3 (TashAT1/3) were derived from a recent duplication event. The predicted amino acid sequence of TashAT1/3 contained four AT hook motifs, a nuclear localisation signal and a signal sequence. Northern blot analysis revealed that TashAT1, TashAT2 and TashAT3 mRNA were down regulated early, during differentiation to the merozoite in vitro. However, no down regulation was observed for any of the TashAT transcripts in a cell line that was severely attenuated with respect to parasite differentiation. Sequence analysis of the upstream regions of TashAT1/3 identified a motif element (TashUM) located 43bp upstream of the putative transcription start site of TashAT1/3 that was highly related to a sequence upstream of TashAT1 and another, unrelated macroschizont gene, Tash1. Preliminary electromobility band shift analysis of TashUM revealed that it bound to a factor found in host and parasite enriched nuclear extract, which appeared to decrease in abundance as the parasite differentiated towards merogony. Antisera generated against a region of TashAT1 failed to recognise a TashAT1 polypeptide by Western blot analysis. However, a 180kDa polypeptide that was down regulated with respect to merogony and co-localised to the host nucleus was specifically recognised. The detected polypeptide was identified as TashAT3 on the basis of size, sequence identity and predicted expression profile. Immunofluorescence analysis showed that the anti-TashAT1 antisera reacted against both the host nucleus and parasite. This reactivity was lost as the parasite differentiated to the merozoite. The host reactivity was probably due to recognition of TashAT3, while it could not be concluded that the parasite reactivity was directed against TashAT1. Taken together, the results indicated that TashAT3 and possibly TashAT1 are additional candidates for parasite encoded factors that are translocated to the host nucleus, bind to DNA and alter host cell gene expression. This modulation of gene expression could directly or indirectly alter the phenotype of the host cell and be involved in parasite dependent regulation of leukocyte cell division.

The hypothesis was that the cellular architecture of the lymphoid tissue was determined by antigenic stimulation. In order to test that hypothesis chickens were produced and maintained in an environment as free from antigens as possible. The chickens were then challenged with an antigen and the cellular changes in the lymphoid tissue, especially the spleen, examined. The thesis thus falls into three sections. In Section 1, after the concept of germ-free life was introduced, the practical problems of producing and maintaining germ-free chickens were discussed in relation to the needs of the present work. A detailed description then followed of the method by which germ-free chickens were produced and maintained in this study. The use of the germicide "Portex D.C.R." was described for sterllizing the surface fertile a eggs in order to obtain germ-free chickens. In Section II the lymphoid tissue of the conventional chickens was described. In order to form bose-line or norm for the study of the effect of antigens in germ-free chickens the lymphoid tissue of the four weeks old unstimulated germ-free chicken was stufied. Serum proteins from these birds were immuncelectrophoresed. It was shown that in the unstimulated four week old germ-free chicken no germinal centres were present in the spleen and that there were fewer cells of the plasmacellular series when compared with four week old conventional chickens. The level of immune-globulins was lower in germ-free chickens than in conventional chickens. Having established this norm it was then possible (Section III) to challenge the germ-free chickens with an antigen in an attempt to induce germinal centre formation and study the way in which germinal centres were formed. The tissues from the germ-free chickens stimulated with a known antigen were examined using conventional histology and immunofluorescence; serum antibodies were estimated and serum proteins were immunoelectrophoresed. In experiment I an attempt was made to induce germinal centre formation in conventional birds using Shigella glexneri as antigen. In the next two experiments a soluble protein antigen (Human serum albumin) was administered to seven day old germ-free chickens (expt. 2) and to seven day old conventional chickens (expt. 3) to induce germinal centre formation. In the remaining three experiments a staphylococcus isolated from a chickens was used as antigen. Germ-free chickens were given the staphylococcus as a primary injection at seven days old (expt. 4) and at twenty-one days old (expt. 5) and as a secondary injection at twenty-one days old (expt. 6) following a primary at seven days old. From there experiments it was concluded that the cellular architecture of the same age was not the same. In germ-free chickens both the soluble protein antigens (HSA) and the particulate antigen (staphylococcus) induced proliferation of cells of the plasmacellular series but germinal centres were found in the spleen following stirculation with staphylococcus. Further, the response to the same dose of the same antigen (staphylococcus) varied with the age of the chicken during the neonatal period. A greater number of germinal centres and a greater proliferation of cells of the plasmacellular series was induced following injection of staphylococcus into 21 day old germ-free chickens than into 7 day old germ-free chickens. A secondary challenge with staphylococcus at 21 days old in germ-free chickens following a primary injection at 7 days old induced a greater number of germinal centres than a primary injection at 21 days old. The germinal centre appeared to be formed in the spleen not by rapid multiplication of a small focus of cells but by aggregation of haemocytoblasts in the periarteriolar lymphocyte sheath. Lymphocyres did not appear to be incorporated in germinal centre formation but seemed to be formed from haemocytoblasts within the germinal centre. No cellular changes were induced in the thymus or bursa of Fabricius following antigenic stimulation of germ-free chickens. It was clear from the experimental work that the cellular architecture of the spleen of the chicken was dependent upon immunogenic stimulus.

This thesis is principally concerned with the construction and development of a sustained release bolus system supplying a range of trace elements to ruminant livestock. The system is a patented invention of the University of Glasgow. Section 1 describes the technology of construction. A compressed mixture of common inorganic salts in cylindrical form (25 mm diameter, 40-100 mm length) is coated by dipping in a polyester resin leaving one flat end uncoated. Release of material into the reticulo-rumen is partly by dissolution and partly by mutual erosion of two boluses administered together. The initial prototype contained copper oxide, manganese sulphate, zinc oxide, zinc sulphate, sodium selenite, cobalt sulphate and potassium iodide with Vitamins A, D3 and E. Section 2 presents results of the examination of a range of factors which might affect the rate of release of nutrients from the bolus. These included the number of coats of resin and the initial length of the bolus. The compositional specification of zinc oxide (a major ingredient) was found to be of great importance and strict control was necessary to produce the required overall release rate. Changes in the inclusion of zinc sulphate could also markedly affect the dissolution/erosion characteristics. An increased number (1-3) of boluses simultaneously administered and the presence of metallic residues (end weights, tubes, cylinders) from other bolus systems was demonstrated to greatly increase the rate of release of material from the bolus. Section 3 describes a series of trials at different sites with grazing cattle judged by the local veterinary surgeons to require supplementation with one or more of the trace elements. The adequacy of supplementation was assessed by the measurement of blood parameters in comparison with untreated animals and/or animals given alternative supplementation as injections or alternative boluses. It was concluded that the bolus system provided adequate copper and selenium to cattle (130-500 kg liveweight) as judged by the responses in plasma copper and glutathione peroxidase activity and that these responses were as favourable as those found by injection of copper and/or selenate containing products. No sound conclusions regarding the effectiveness of the bolus system in supplying cobalt could be made due to the possible limitations of the assay method (and its interpretation) for Vitamin B12. There were no indications of cobalt inadequacy in the cattle. Section 4 of the thesis examined the possibility that the bolus construction with a modified matrix might be capable of providing a constant release of a variety of medicaments. Limited exploratory trials were conducted to examine the possible inclusion of materials such as levamisole hydrochloride, ivermectin, oxfendazole, laidlomycin propionate and Vitamin E. Distinct possibilities were found but much further work would be required to establish formulations giving appropriate and constant release of materials in the normally accepted therapeutic range. Section 5 examined the possibilities for the development of a comparable, but smaller (19 mm diameter) bolus appropriate for use in sheep. Regurgitation was a major problem but was effectively eliminated by increasing the overall density to 3.0 g/ccm. The cost of manufacture would be such as to allow the use of only a single bolus. The absence of loss by mutual erosion between two boluses was found to lead to little further weight loss in prototypes after about 60 days. Nevertheless, analyses of faeces and of livers recovered at slaughter demonstrated the effectiveness of the copper contained in the bolus. These were such as to give concern about the possibility of potential copper toxicity. In Section 6 an assessment was made of the effectiveness of a high density carbo-wax matrix as a carrier for avoparcin in an alternative bolus system. Comparisons were made by evaluation of the avoparcin concentrations in faeces with that resulting from a constant daily in-feed addition of avoparcin. Assessment of faecal output indirectly by estimation of the chromium content of faeces resulting from constant addition of the inert marker to the constant diet given to all cattle showed the experimental bolus construction to be irregular and erratic in relation to the direct inclusion in feed.

Reasons for performing this study: Metacarpal/metatarsal III condylar fractures are the most common type of fracture associated with Thoroughbred horseracing in the UK, and the most common reason for euthanasia on the racecourse. Prediction of fracture through quantification of exercise-related radiographic changes could enable modification of horse management to prevent this injury, improving animal welfare and reducing wastage. Objectives: The general aims were to validate objective radiographic measurement of exercise-related modelling in distal metacarpal III of Thoroughbred racehorses and to explore their utility for fracture prediction by comparing measurements from horses that sustained a fracture of the lateral condyle of distal metacarpal III with those from controls. The initial objective was to establish methods to measure objectively the following variables in distal metacarpal III: condyle opacity, cortical thickness and metaphyseal angle. Radiographic measurements were correlated with equivalent measurements derived from computed tomography (CT) to determine their accuracy. The second objective was to explore the ability of the radiographic measurements to identify horses at risk of fracture. This was done initially by comparing measurements made from radiographs taken at a single time point between Thoroughbred racehorses with and without a lateral condylar fracture, and subsequently by analysis of measurements from series of radiographs obtained prior to and at diagnosis of lateral condylar fracture as part of routine clinical practice. For the final objective, the maximum density of the palmar condyles of distal metacarpal III was determined using a quantitative CT-based technique. Maximum density was compared between horses with fractures and those without, and comparison made with the maximum opacity measured from radiographs, to investigate whether these measurements could be used to identify horses at risk of fracture. Materials and Methods: Fifty-five metacarpal III bones obtained from Thoroughbred racehorses euthanized on UK racecourses (age range 3-11 years) were divided in to three groups: control (no distal limb fracture, n=30), non-fractured (contralateral limb lateral condylar fracture, n=11) and fractured (lateral condylar fracture, n=14). All limbs were subjected to radiography and computed tomography for measurement of diaphyseal cortical thickness 2.5cm distal to the nutrient foramen (expressed as dorsal cortex:medulla width) and metaphyseal angle (deviation of the metaphysis relative to the diaphysis). Measurement of radiopacity of the medial and lateral condyles was calibrated using an aluminium phantom i (condyle:phantom ratio). Correlation between radiography and CT measurements and comparison of radiography measurements between groups was performed. For the longitudinal study, medical records of the Singapore Turf Club were reviewed. Thoroughbred racehorses diagnosed with a lateral condylar fracture that had also been radiographed in the previous 24 months were identified and placed in the ‘high risk’ group (n=16). Horses radiographed and then raced for a minimum of 2 years without suffering a fracture were placed in the ‘low risk’ group (n=15). Twenty-seven metacarpal III bones obtained from Thoroughbred racehorses euthanized on UK racecourses (age range 3-10 years) were used in the investigation of maximum density of the palmar condyles. They were divided in to three groups: control (no distal limb fracture, n=10), non-fractured (contralateral limb lateral condylar fracture, n=8), and fracture (lateral condylar fracture, n=9). Computed tomography measurement of condyle density was calibrated using a potassium phosphate phantom to enable comparison between age-matched bones. Results: Diaphyseal cortical thickness and metaphyseal angle measurements made by radiography and CT were significantly correlated (r=0.74, 0.73; p=0.007, 0.004) but there was no significant difference in measurements between groups. Radiopacity of medial and lateral condyles was significantly greater in non-fracture (0.67±0.04, 0.68±0.04) and fracture (0.82±0.07, 0.68±0.09) groups than the control (0.59±0.08, 0.57±0.09) group (p=0.003). The medial condyle (0.82±0.07) was significantly more radiopaque than the lateral condyle (0.68±0.09) in the fracture group only (p=0.001). In the longitudinal study, the dorsal cortex was thicker in high risk than low risk horses, the mean ± SD cortical thickness ratio of the high and low risk groups was 1.36 ± 0.26 and 1.08 ± 0.19 respectively (p=0.008). Metaphyseal angle measurement displayed a similar pattern and the difference was statistically significant, the mean ± SD metaphyseal angle of the high and low risk groups was 9.65° ± 2.21 and 6.95° ± 1.65 respectively (p=0.000). Computed tomography measurement of maximum density of distal metacarpal III, found no significant difference in maximum density of the lateral and medial palmar condyle between groups. There was a significant correlation between age and maximum density of the lateral condyle (r=0.44, p=0.019) and medial condyle (r=0.54, p=0.003). ii Conclusions: Objective measurement of dorsal cortical thickness and metaphyseal angle of distal metacarpal III can be performed accurately and precisely using radiography in Thoroughbred horses. Radiographic measurement of condyle opacity was precise but conclusions about the accuracy of this measurement await comparison with an appropriate reference standard. Increased radiopacity of the distal condyles was identified in horses that sustained lateral condylar fracture. However, this finding was not reflected by data from the horses represented by the clinical radiographs, suggesting that this measurement may not be useful in identifying horses at risk of fracture. Evidence supportive of this conclusion was provided by maximum density measurements made by CT. Significant differences in dorsal cortical thickness and metaphyseal angle were found between horses that sustained a lateral condylar fracture and horses that underwent radiography for clinical reasons but subsequently raced without fracture, suggesting that these variables could be of value in determining the risk of fracture and merit further investigation.

No description available.

Two methods were used in this research. The pedobarograph is a relatively novel method of gait analysis for animals which enables footfall patterns to be recorded, enabling spatial parameters (step length, width and angle) and plantar pressure patterns to be described and measured. A Kistler force plate was then used to measure the three-dimensional ground reaction forces (GRF's) produced during walking. Speed and cadence can be calculated using either system. Gait patterns are described for normal birds, and for different strains of broilers, raised on different feeding regimes. All the gait parameters were very variable, both between birds, and within the same bird, even when bodyweight and speed were controlled for. Despite the high variability, however, significant differences were identified in many of the gait parameters between the different groups. The vertical and craniocaudal GRF's of Brown Leghorns showed similar characteristics to those produced in human walking. The peak vertical forces were of a similar order of magnitude in the birds as in humans (125-150 % bodyweight), and the peak craniocaudal forces, and the rate of change of force, were closely tied to speed. All the GRF's in the birds increased significantly with increasing speed, except for braking rate (which was more variable) and stance time (which decreased significantly). The mediolateral forces were much greater in the birds than have been reported for other species, however, with peaks of 10-22% bodyweight. Analysis of plantar pressures showed that the pressure were concentrated on the digital pads, with the lowest pressure on the metatarsal pad (131 kNm-2), and highest pressure on the medial toe (up to 218 kNm-2).Combined gait analysis and morphometric studies of ad libitum-fed selected broilers identified many ways in which their gait deviated from that of relaxed broilers and Brown Leghorns, in ways which would serve to increase stability and decrease stresses on the skeleton.

Canine degenerative myelopathy(DM) is a late onset neurodegenerative disease that primarily affects German Shepherd dog (GSD), though a number of other specific breeds are also affected. The underlying cause of the disorder remains elusive, though recent advances have implicated a mutation of superoxide dismutase 1(Sod1) in the aetiology, also implying DM is a potential orthologue of human amyotrophic lateral sclerosis. The identification of the Sod1 mutation raises the index of suspicion for an individual animal, however it is not specifically diagnostic as a proportion of dogs homozygous for the Sod1 mutation do not develop DM. Therefore, there is a clinical need for the development of specific biomarker(s) for DM to support genetic test. The aim of this study was to establish potential biomarkers for DM by exploring canine cerebrospinal fluid (CSF). A dual strategy was adopted;1) Evaluation of potential ALS biomarkers in DM CSF, 2) Identification of novel biomarker(s) in DM CSF. The cases selected in this project had a presumptive diagnosis of DM and were homozygous for Sod1 mutation. Preliminary characterisation by Western blot and mass spectrometry identified four protein candidates in DM CSF, comprised of cystatin C, transthyretin (dimeric and monomeric TTR), haptoglobin and clusterin. Since the validity of these putative biomarkers may be influenced by pre-analytical variables that may arise from the clinical environment, we therefore assessed the impact of three potential sample handling practices on these four proteins. The results from these experiments demonstrate that dimeric TTR and clusterin were affected by sample handling conditions. Therefore, an appropriate protocol for CSF sample handling was established. Western blot analyses indicated that clusterin is the most viable biomarker candidate for DM. Clusterin was significantly elevated in DM CSF when compared to a range of neurological conditions. The second potential candidate for DM biomarker is TTR, which is potentially reduced, an observation similar to those found in ALS CSF. The relationship of these proteins in the pathogenic mechanisms that underpin DM is unclear. However, based on observations on ALS, it is reasonable to speculate that their alterations are associated with a toxic gain of function of the mutant SOD1 protein. The successful characterisation of clusterin and TTR in DM CSF may therefore represent components of a panel of emerging biomarkers that may combine to distinguish DM in the clinic and provide further insights into the disease mechanisms.