Evidence-based veterinary medicine (EVM) has the potential to improve welfare of equine patients in primary care practice by ensuring that decision making at the point of care is underpinned by credible research. Patient focussed care requires consideration of a combination of evidence, veterinary judgement, experience and owner associated variables to ensure the best possible outcomes for the animal, whilst maximising the impact of EVM on equine health and welfare. A holistic approach to development and implementation of EVM, that involves horse owners, other equine stakeholders and veterinary surgeons, will ensure that all parties involved in decision making on behalf of equine patients are engaged in evidence-based decisions. The central aim of the thesis was to determine how advances in evidence-based veterinary medicine had the potential to achieve the greatest impact on equine health and welfare. The objectives were to: • Review methods of implementing evidence-based medicine in clinical practice and determine their suitability for veterinary medicine. • Describe the prevalence and outcome of conditions seen for ‘out of hours’ primary assessment in equine practice. • Investigate horse owner perception, understanding and approach to the most common emergency conditions. • Identify paucities in the knowledge and resources available to equine owners and highlight the information required to implement and facilitate evidence-based decision making. • Use an evidence-based approach to develop and disseminate an educational resource for horse owners to improve understanding of an emergency condition and equine welfare associated with that specific disease. The first section of the thesis aimed to identify a common emergency condition with a major welfare impact, which would become a focus for research in subsequent studies. A combination of methods were used in these chapters including a retrospective case study of ‘out of hours’ case records from two practices over a three year period, and a mixed methods online survey of opinions and experiences of equine yard owners. In the retrospective case study, colic (abdominal pain) was the most common condition seen as an ‘out of hours’ emergency at both veterinary practices, accounting for approximately a third of the ‘out of hours’ caseload. The three most common reasons for ‘out of hours’ visits for both practices were colic (35%), wounds (20%) and lameness (11%). The majority of cases seen ‘out of hours’ required a single treatment for resolution of the presenting problem (58%), whilst 26% needed multiple treatments. An online survey consisting of open and closed questions was distributed to UK livery yard owners. The survey investigated participants’ demographics and experiences, their opinion of the most common emergency conditions in the horse, and decision-making in emergency situations. Descriptive analysis of data included frequency ranking and categorisation of free text responses. There were 104 survey participants. The majority had kept horses for more than ten years (97%), and had previous experience of emergency conditions (99%), predominantly of colic (96%) and wounds (92%). Participants considered that the most common emergency conditions were colic (98%), wounds (49%) and fractures (22%), and the most concerning conditions were colic (94%), lameness (36%) and wounds (21%). Factors important in emergency decision making were: degree of pain, likelihood of condition resolving, and severity of disease. The results of these studies provided the impetus for using colic as the focus for the next phases of work within this thesis. The second section of the thesis investigated veterinary practitioners’ and horse owners’ approaches to horses with abdominal pain, with the aim of identifying where knowledge or resources were good or were variable or lacking. The subset of horses with abdominal pain from the ‘out of hours’ retrospective case series were explored to describe how these animals presented to veterinary surgeons, how they were diagnosed, treated and the outcomes. The clinical signs associated with a ‘critical’ outcome of colic were determined using univariate logistic regression. In the retrospective case series, 941 cases presented with signs of abdominal pain; 23.9% (n=225/941) cases were categorised as ‘critical’, and 18% (n=168/941) were euthanased. Fifteen variables from the case presentation significantly correlated with a critical case (p < 0.01) and were therefore incorporated into the multivariate model. The final multivariable model included three variables significantly associated with the likelihood of a case being classified as ‘critical’: increased heart rate (p < 0.01), abnormal mucous membrane colour (p < 0.01) and absence of borborygmi in at least one quadrant (p < 0.01). These were considered to be essential clinical parameters associated with the differentiation of critical cases of colic, and therefore should be included in the veterinary assessment of the condition. To investigate horse owners’ opinions and experiences, a mixed methods survey was distributed to investigate owner knowledge, experience and approaches to colic through open and closed questions and clinical scenarios. The survey also aimed to highlight knowledge and resource gaps that may affect the welfare and outcomes of horses with abdominal pain. The horse owner survey identified that owners had variable and often limited knowledge of colic and were frequently poor at recognising some of the clinical and behavioural manifestations of the condition. This study also identified the need for an all-encompassing educational resource for horse owners underpinned by scientific evidence in an accessible and functional format. Developing evidence-based resources for veterinary practitioners and horse owners was beyond the scope of what could be achieved within this thesis. Educational colic resources for horse owners (‘REACT’) were collaboratively developed and disseminated by Nottingham Equine Colic Project (including the author of the thesis) and The British Horse Society. Current evidence and literature on methods of incorporating evidence into clinical decision making were reviewed within the thesis, specifically accounting for the difficulties faced in veterinary medicine. Future work is needed to develop evidence-based resources on colic for veterinary surgeons to ensure that scientifically underpinned decisions are made at the point of care. The work contained within this thesis highlighted the importance of the owner in the recognition of disease and instigation of veterinary intervention. It is crucial that both equine owners and veterinary surgeons are considered in equal measure when investigating decision making on behalf of a horse. Owners are the gatekeepers of animal care and welfare and therefore there is a requirement that they are included in research and the development of educational material. Veterinary directed studies are commonplace, however the benefits of such research are questionable if the horse owner does not present their animal for veterinary attention. The legacy of this study will likely be the inclusion of horse owners in the development of evidence-based educational campaigns.

The aim of this study was to investigate intervention strategies that have the potential to produce treatments reducing rotavirus-related disease in swine. Rotavirus is the biggest cause of viral gastroenteritis in young swine so is a huge economic burden to farmers. Cell lines deficient for innate anti-viral mechanisms were used to passage rotavirus. This novel vaccine strategy was investigated for its ability to elicit virus that is dependent on the modified cell lines for efficient replication and growth. Rotavirus isolates dependent on modified cell lines represent promising attenuated viral vaccine candidates. Whilst no rotavirus isolates were discovered with this characteristic, analysis of the viral genome after serial passage revealed non-synonymous single nucleotide polymorphisms causing non-conserved mutations at the protein level. Rotavirus isolates with these mutations may cause cell line dependency. A second intervention strategy used computer-assisted analysis (in silico) to reveal short potentially therapeutic peptides based on possible epitopes of rotavirus capsid proteins. Each synthetic peptide was not shown to block the rotavirus-host cell interaction in vitro. Peptides with this property could be used as candidate peptide-based anti-viral blocking drugs. In addition, peptides did not block the neutralising ability of anti-rotavirus antibodies found to be present in pig serum, which would then be used as immunogens to raise neutralising antibodies against rotavirus. However, inactivated rotavirus was found to bind serum antibodies in vitro and therefore appears to hold more promise as a therapeutic strategy than the synthetic peptides. Antibodies present in sow serum were discovered to cross-react with four different lab adapted strains of rotavirus. In contrast, antibodies directed against a common porcine genotype (G5P[7]) were not crossreactive against other strains. This study has initiated research into treatments against rotavirus-related disease in swine but potential vaccine and therapeutic candidates have not yet been revealed.

Patient safety is an active field of research in medicine and the driving force behind healthcare policy and practices to ensure the delivery of safe, quality patient care. However, it is a concept in its infancy in the veterinary profession. Veterinary medical error is under reported, poorly understood and inadequately managed with consequences for patients, owners and clinicians. The aim of this thesis is to explore the causes and types of error in veterinary practice and develop solutions to improve patient safety, and by extension quality of care for veterinary patients. A mixed methodology was employed in the investigation of this aim, with data gathered by focus groups, insurance claim review and questionnaires. The findings of the study suggest that the causes of error in veterinary practice mirror those in other safety critical industries, namely individual errors and system failures. These findings led to the development of a reliable, validated safety culture survey for veterinary practice, to assess and understand the attitudes which drive safety critical behaviours of veterinary staff. This survey was then used as a pre and post training measure to assess the effectiveness of a teamwork training programme, VetTeams, as an intervention to improve safety culture, and by extension patient outcomes in veterinary practice. The outcomes of this study are a framework to inform the understanding and analysis of veterinary error, a measurement tool of veterinary safety culture and a training programme for veterinary teams which addresses the non technical skills identified as critical to preventing mistakes. The findings suggest that changing attitudes to error through an understanding of the causative factors and education in non technical skills, is essential to drive behaviour change in clinicians and enable improved delivery of clinical care.

Lameness was described by the Farm Animal Welfare Council (2009) as one of the foremost health and welfare challenges facing dairy cattle in the UK. Studies suggest UK lameness prevalence has increased over the past 30 years peaking at 36.8% in 2006-2007. The first study in this thesis aimed to investigate current lameness prevalence and related management practices in the UK. Short, structured interviews were conducted with farmers on 43 randomly selected farms in central England during spring 2014 before mobility scoring the lactating herd. Mean herd lameness prevalence was 30.1% (range 7.3%-60.6%). This represents a drop in prevalence since 2007, suggesting a corner may have been turned in control of lameness. A large proportion of farmers reported conducting their own routine trimming and treatment of lame cows. It is therefore important to ensure correct training reaches these farmers if lameness prevalence is to continue to fall. Lameness is often associated with claw horn lesions (sole ulceration and white line disease) however little information is available in the scientific literature on treatment protocols for these lesions. This second study in this thesis aims to begin to address this knowledge gap through a partially blinded, randomised, positively controlled clinical trial (RCT). Animals with an acute case of lameness (two non-lame scores followed by a lame score determined by fortnightly mobility scoring) resulting from claw horn lesions on a single, hind claw were enrolled and allocated at random one of four treatments: 1) Therapeutic trim (TRM) (positive control group), 2) therapeutic trim and foot-block (TB), 3) therapeutic trim and nonsteroidal anti-inflammatory drug (NSAID) (TN) and 4) therapeutic trim, foot-block and NSAID (TBN). One hundred and eighty-three cows were enrolled over a 13-month period. Based on a sound score (score 0) at 35 days post treatment, the number (and proportion) of successful treatments was 11 of 45 (24.4%) TRM, 14 of 39 (35.9%) TB, 12 of 42 (28.6%) TN and 23 of 41 (56.1%) TBN. A significant difference was seen between treatment groups (P=0.01). The results of this study suggest that recovery in animals treated for lameness due to claw horn lesions is maximised by treatment with a TBN. Smaller non-significant improvements were also seen in TB and TN compared with a TRM. The lesions treated in this RCT were largely mild due to the early recognition and treatment protocol used. Studies have demonstrated delays in identification of lame cows on farms and so the lesions seen in this study may not represent those treated by farmers, foot trimmers and vets in the field. The third study in this thesis aimed to investigate the impact of chronicity of lameness on treatment outcomes. The prospective, partially blinded, positively controlled RCT followed a similar protocol to the previous RCT but enrolled cows lame on the same hind leg for at least two of the last three mobility scores. Animals were randomly allocated one of three treatments: 1) therapeutic trim only, 2) therapeutic trim and shoe or 3) therapeutic trim, shoe and NSAID. Three outcomes at 42 (±4) days post treatment were analysed: (i) non-lame (score 0 or 1 at outcome), (ii) improved (lower mobility score at outcome than enrolment) and (iii) apparent leg cure (non-lame on treated leg or lame on contralateral leg at outcome). Over a 13-month period, data was collected for 189 cases of lameness from 176 cows (13 cows received treatment on both hind limbs). No significant difference between treatment groups was seen for any of the outcomes analysed. A very low response rate to treatment of around 15% was seen across all treatment groups. Data for all animals treated in this chronic lameness RCT (CLRCT) was compared to a subset of data from the acute lameness RCT (ALRCT). Analysis showed a significant difference for outcomes (i), (ii) and (iii) in animals treated for acute compared to chronic lesions (P < 0.01). In the ALRCT, 31 of 127 treated animals were lame at outcome (15 lame on the opposite hind leg to enrolment). In the CLRCT 132 of 156 treated animals were lame at outcome (60 lame on the opposite hind leg to enrolment). These findings support the need for both early and effective treatment and suggest that animals should receive appropriate treatment interventions in both hind limbs even if presenting with unilateral lameness. To have an impact on lameness prevalence, it is essential that research findings are disseminated to farmers treating cows on farms. The final study in this thesis aimed to assess the efficacy of different methods of knowledge transfer (KT) in relation to this. A prospective, qualitative and quantitative study was conducted to assess three methods of cattle lameness KT; 1) paper based/online AHDB dairy resources (positive control group), 2) resources plus facilitated discussion group, 3) resources plus on-farm visit by ‘expert’ veterinary surgeon. Prior to the KT session participants completed a semi-structured interview and observed video clips of lame and non-lame cows to select how quickly they would treat each case. Following the KT session the video exercise was repeated and a feedback form completed. Video clip responses were analysed pre-and post-session. Feedback forms were used to assess engagement and likelihood of behavioural change. Fifty-one individuals participated in the study. ‘Expert’ visits had a significant positive effect on the farmers’ awareness of the ‘correct’ maximum treatment interval advised for lame cows compared to resources alone. ‘Expert’ KT sessions were also felt to be significantly more enjoyable and useful. A narrow range of feedback scores suggest this method was also most accessible to a range of learners. The findings of this study suggest the role of the veterinary advisor remains central to the KT process. The key messages derived from the research undertaken in this thesis are the need for early identification and prompt, effective treatment of claw horn lesions in dairy cows. As the body of research grows it is imperative that suitable knowledge transfer strategies are employed to best disseminate these findings to farm-level and maximise their impact on the health and welfare of affected animals.

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No description available.

Evaluation of feeding varying levels of digestible lysine on broiler breeder male reproductive characteristics and body weight changes

Lameness is the greatest health and welfare concern in sheep flocks in the U. K. This thesis presents research on epidemiology of lameness in sheep Most previous studies quantifying lameness and its causes are based on the premise that farmers can identify the causes of lameness and recognise lame versus sound sheep. In 2005, a postal questionnaire was sent to a random sample of English sheep farmers to investigate whether farmers could correctly name six common foot lesions in sheep (interdigital dermatitis (ID), footrot (FR), contagious ovine digital dermatitis (CODD), shelly hoof, foot abscess and toe granuloma) from a characteristic picture and a written description. The same questionnaire of six lesions was presented at a meeting of specialist sheep advisors, primarily veterinarians. Approximately 20% of farmers and 80% of sheep specialists named all 6 lesions correctly, indicating a gap in knowledge between sheep advisors and sheep farmers. In addition, farmers tended to name any hoof horn damage as footrot which might imply that some lame sheep receive incorrect treatment. Management factors associated with the prevalence of farmer estimated lameness (irrespective of farmer recognition of lesions) and the adjusted prevalence of lameness caused by ID and FR among flocks where farmers correctly recognised both lesions were investigated and compared in negative binomial regression models. Farmers who routinely foot trimmed and frequently footbathed their sheep reported a higher prevalence of lameness, ID and FR. Farmers who stocked their sheep at >8ewes/hectare reported a high prevalence of both lameness and ID whilst those who separated `some' or `all' lame sheep at pasture reported a low prevalence of both lameness and ID. Farmers in the east of England reported a lower prevalence of lameness, ID and FR compared with central England. A numerical rating locomotion scoring scale (0-6) was developed to monitor locomotion in sheep in a research setting. There was good agreement between and within trained observers using this scale. This scoring system was used in a longitudinal study on one farm, two groups of sheep (30 in each group) with different treatment regimes (antibiotic injection & antibiotic spray vs. foot trimming and antibiotic spray; and occasional footbathing) for lameness with FR and ID were followed for five weeks to investigate the temporal associations between ID, FR and the effect of different treatments on locomotion. From the examinations it was concluded that even mildly lame sheep can have FR and ID. In a multilevel linear mixed model, there was a significant association between ID, FR and locomotion score with the mean score of 0.25 increasing to 0.43 for sheep with ID and to 2.18 for sheep with FR. In addition, sheep that developed FR had a significantly raised locomotion score the week before FR became clinically apparent. Treatment with antibiotic injection and antibiotic spray significantly reduced the locomotion score of sheep the following week. The movie clips from the locomotion scoring reliability study were used to investigate farmer and sheep specialist recognition of lame sheep and decisions on whether to catch them. A group of farmers from three regions (Devon, Newark and Norfolk) and sheep specialists at a Sheep Veterinary Society meeting were shown eight movie clips of sheep with varying locomotion scores. Although the majority of farmers and sheep specialists identified mildly lame sheep with a locomotion score of 2, only 50% of them would catch such a sheep if it was the only lame sheep in the group. Most farmers and sheep specialists did not catch lame sheep until the lameness was locomotion score 3 or 4. The more frequently farmers caught lame sheep, and the milder the lameness when a decision to catch was taken, the lower the farmer reported prevalence of lameness in the flock. The research in this thesis suggests that farmers, who are the primary carers for lame sheep, do not always name foot lesions correctly and so sheep may receive inappropriate treatment for some lesions. In addition, whilst farmers and sheep specialists can recognise lame sheep, they do not always catch and treat mildly lame sheep. Farmers who caught all mildly lame sheep within a few days of seeing them lame reported a lower prevalence of lameness in their flock. This might be explained by the evidence from this thesis that mildly lame sheep can have FR or ID and so prompt treatment of these lame sheep reduces the prevalence and incidence of FR and ID.

Four longitudinal studies were conducted. The first study investigated the longitudinal pattern of udder half somatic cell count (HSCC) and intramammary infection (IMI) in 48 UK suckler ewes over the first 10 weeks of lactation. This was the first study to demonstrate that HSCC of suckler ewes followed a quadratic and cubic relationship with days in lactation over the first 10 weeks of lactation. Udder half somatic cell count was also explained by presence of bacteria. Ewes older than 6 years of age had significantly higher HSCC than younger ewes. The second study investigated the relationships between udder conformation, SCC and lamb weight. Whilst accounting for lamb age and birth weight, significantly lower lamb weight was associated with a ewe SCC of >400,000 cells/ml (-1.7 kg), a traumatic teat lesion (bite, tear or chapping) 2 weeks previously (-1.1 kg), and a ewe body condition score (BCS) of <2.5 before lambing (-1.3kg). Higher HSCCs were observed in ewes with a lower suspended udder, and older ewes in poorer body condition. The findings from this study make an important contribution to the knowledge of the impact of udder health of suckler ewes by demonstrating that udder conformation is associated with IMI and that IMI and teat damage are negatively associated with lamb weight. The third study investigated the effect of dry cow therapy (DCT) on subclinical mastitis in a lowland flock with a low incidence of clinical mastitis by recording HSCC and lamb weights in the following lactation. To the author’s knowledge, there are no published reports of the effect of broad spectrum DCT on subclinical mastitis in suckler ewes in the literature. No significant effect was found between the use of DCT and HSCC or lamb weight in the subsequent lactation. The fourth study was a randomised controlled trial to assess the effect of DCT on clinical mastitis in a suckler flock with a high level of clinical mastitis. Dry cow treatment significantly reduced the incidence of clinical mastitis over one year, with a 70% reduction of clinical mastitis in ewes that received treatment from 6.2% to 1.8%. This was the first field trial to investigate and demonstrate the clinical benefit of the use of a broad spectrum DCT in suckler ewes. These studies have enhanced our knowledge of longitudinal patterns of infection and demonstrated the importance of udder health for optimising production of suckler ewes. Factors to control for when using SCC as a tool to measure intramammary infection were described.

Three experiments were conducted to determine the effects of grain processing, grain sources, lactational performance and nutrient digestion in dairy cows. In trial 1 (56 d), 40 cows were divided into five groups and fed diets containing 40% grain as dry-rolled sorghum (DRS, 643 g/L), steam-flaked sorghum (SF) processed to result in three different flake densities: SF34 (34 lb/bu or 437 g/L), SF28 (28 lb/bu or 360 g/L), and SF22 (22 lb/bu or 283 g/L); and dry-rolled barley (DRB). Feeding steam-flaked sorghum grain or dry-rolled barley did not increase milk yield and milk protein content and yield. However, due to a lower intake of dry matter, feed efficiency was 10 to 19% higher for flaked sorghum and barley diets compared with DRS. Steam-flaking also decreased milk urea-N and tended to increase milk casein. In trial 2 (58 d), 32 lactating cows were divided into four groups and fed diets containing 39% sorghum grain as dry- rolled sorghum (DRS), or steam-flaked sorghum (SF) processed to result in similar flake densities as trial 1: SF34 (34 lb/bu or 437 g/L; SF28 (28 lb/bu or 360 g/L); and SF22 (22 lb/bu or 283 g/L). When sorghum grain was moderately flaked (SF34 and SF28) milk and 3.5% FCM yields were not increased compared to DRS, however, efficiency of feed utilization again was higher for SF34 and SF28 due to lower intake of dry matter. The very thin flake (SF22) had a negative effect on milk and 3.5% FCM compared with DRS, SF34, and S F2 8. Digestibilities of nutrients were increased by steam-flaking compared with dry-rolling. In trial 3 (58 d) twenty four cows were assigned to three treatments in which diets contained.8% urea (Urea), 6% soybean meal (SBM), or 5% fish meal (FM) as the protein sources. Intake of DM was highest for Urea, intermediate for SBM, and lowest for FM. Higher producing cows (46 Kg/d of milk) responded more positively in milk and FCM yields and feed efficiency to SBM and FM compared with those fed Urea. Cows producing about 35 Kg/d of milk tended to perform better when fed Urea than when fed SBM or FM. Digestibilities of nutrients were not affected greatly by protein source.