Law Shun-ying, Shirley. / Thesis submitted in: June 2003. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 134-138). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / List of Tables --- p.iv / List of Figures --- p.vi / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- The Hong Kong Jockey Club --- p.1 / Chapter 1.2 --- History of Sand Mesh System in Hong Kong --- p.2 / Chapter 1.3 --- Problems Encountered in Track Maintenance --- p.3 / Chapter CHAPTER 2 --- CONCEPTUAL FRAMEWORK OF STUDY / Chapter 2.1 --- Sand and Sand Mesh Systems --- p.9 / Chapter 2.2 --- The Basic Components of a Turf Track System --- p.11 / Chapter 2.3 --- Track Characteristics --- p.14 / Chapter 2.3.1 --- Hardness --- p.14 / Chapter 2.3.2 --- Stability --- p.17 / Chapter 2.4 --- Problems Encountered in Sand Mesh Systems --- p.20 / Chapter 2.4.1 --- Maturity of sand mesh system --- p.20 / Chapter 2.4.2 --- Surface instability in the early years after construction --- p.22 / Chapter 2.4.3 --- Shading of sections of the Happy Valley track --- p.24 / Chapter 2.5 --- Objectives of Study --- p.26 / Chapter 2.6 --- Hypothesis of Study --- p.26 / Chapter 2.7 --- Significance of Study --- p.27 / Chapter CHAPTER 3 --- LITERATURE REVIEW / Chapter 3.1 --- Components of a Turf Track --- p.28 / Chapter 3.2 --- Age Development in Sand Based Turf --- p.30 / Chapter 3.3 --- Surface Stability of Sand Rootzone --- p.32 / Chapter 3.4 --- Physical Properties and Botanical Cmposition --- p.34 / Chapter 3.5 --- Significance of Macropores --- p.42 / Chapter 3.6 --- Water Retention --- p.43 / Chapter 3.7 --- Ideal Sand Medium --- p.45 / Chapter CHAPTER 4 --- METHODOLOGY / Chapter 4.1 --- Study Site --- p.46 / Chapter 4.2 --- Sampling Period / Chapter 4.2.1 --- "September, after the commencement of first race" --- p.51 / Chapter 4.2.2 --- Mid-December to January --- p.51 / Chapter 4.2.3 --- April --- p.52 / Chapter 4.2.4 --- "June, before the on-set of summer renovation" --- p.52 / Chapter 4.3 --- Sampling Method --- p.53 / Chapter 4.4 --- Physical Qualities of Sand / Chapter 4.4.1 --- Moisture release characteristics --- p.54 / Chapter 4.4.2 --- Saturated hydraulic conductivity --- p.58 / Chapter 4.4.3 --- Unsaturated hydraulic conductivity --- p.59 / Chapter 4.4.4 --- Oxygen diffusion rates --- p.62 / Chapter 4.5 --- Grass Bio grass / Chapter 4.5.1 --- "Topgrowth, stolons and roots" --- p.63 / Chapter 4.6 --- Performance Indicator / Chapter 4.6.1 --- Track hardness --- p.65 / Chapter 4.6.2 --- Shear strength --- p.67 / Chapter 4.6.3 --- Divot assessment --- p.68 / Chapter CHAPTER 5 --- THE STUDY OF PERFORMANCE INDICATORS AND PROFILE PHYSICAL PROPERTIES / Chapter 5.1 --- Performance Indicators / Chapter 5.1.1 --- Race times --- p.71 / Chapter 5.1.2 --- Shear strength --- p.73 / Chapter 5.1.3 --- Vertical penetration resistance and hardness --- p.77 / Chapter 5.2 --- Analysis of Physical Properties of Sand / Chapter 5.2.1 --- Moisture release characteristics / Chapter 5.2.1.1 --- Age and moisture release curves (MRC) in Shatin Turf Track --- p.80 / Chapter 5.2.1.2 --- MRC and profile design in Happy Valley Old and New Sections --- p.83 / Chapter 5.2.2 --- Saturated and unsaturated hydraulic conductivity / Chapter 5.2.2.1 --- Hydraulic conductivity in Shatin --- p.85 / Chapter 5.2.2.2 --- Hydraulic conductivity in Happy Valley --- p.87 / Chapter 5.2.3 --- Oxygen diffusion rates / Chapter 5.2.3.1 --- ODR and profile age in Shatin --- p.90 / Chapter 5.2.3.2 --- ODR and profile design in Happy Valley --- p.91 / Chapter 5.2.4 --- Grass biomass / Chapter 5.2.4.1 --- Biomass and variation in profile age in Shatin --- p.92 / Chapter 5.2.4.2 --- Biomass and variation in profile design in Happy Valley --- p.93 / Chapter 5.2.4.3 --- Biomass and the effect of shade in Happy Valley --- p.93 / Chapter 5.2.5 --- Track hardness / Chapter 5.2.5.1 --- Track hardness and variation in profile age in Shatin --- p.94 / Chapter 5.2.5.2 --- Track hardness and variation in profile design in Happy Valley --- p.96 / Chapter 5.2.6 --- Shear strength / Chapter 5.2.6.1 --- Shear strength and variation of profile age in Shatin --- p.98 / Chapter 5.2.6.2 --- Track hardness and variation in profile design in Happy Valley --- p.99 / Chapter 5.3 --- Correlation between Soil Physical Properties and Performance index / Chapter 5.3.1 --- Correlation between soil physical properties and shear strength value --- p.100 / Chapter 5.3.2 --- Correlation between soil physical properties and surface hardness --- p.101 / Chapter CHAPTER 6 --- CONCLUSIONS / Chapter 6.1 --- Summary of Findings --- p.118 / Chapter 6.2 --- Implications of Study / Chapter 6.2.1 --- Target levels of performance indicators --- p.120 / Chapter 6.2.1.1 --- Surface strength target level --- p.121 / Chapter 6.2.1.2 --- Surface hardness target level --- p.122 / Chapter 6.2.2 --- Turf management and cultural practice implications / Chapter 6.2.2.1 --- Effect of aging and variations of profile age in Shatin --- p.123 / Chapter 6.2.2.2 --- Effect of different profile design in Happy Valley --- p.125 / Chapter 6.2.2.3 --- Effect of shading in Happy Valley --- p.126 / Chapter 6.2.3 --- Construction material and design --- p.126 / Chapter 6.2.4 --- Managing user intensity --- p.127 / Chapter 6.3 --- Limitations of Study --- p.128 / Chapter 6.4 --- Further Studies / Chapter 6.4.1 --- Shear strength tester --- p.129 / Chapter 6.4.2 --- Maximum life of sand mesh profile --- p.129 / Chapter 6.4.3 --- Problems with newly constructed profile --- p.130

A retrospective investigation of Thoroughbred racehorses euthanazed as result of catastrophic musculoskeletal injury (CMI) at four racetracks in Gauteng, South Africa during the period of 1998-2004 was performed. Fifty-five cases of CMI from 103 603 starts were evaluated. The incidence of CMI per 1000 starts was 0.53, similar to the incidence reported worldwide. The affected limb of 32 of 55 horses with a CMI was evaluated radiographically, ultrasonographically and dissected. CMI occurred unilaterally and predominantly in the forelimbs, the left forelimb (LF) being most commonly affected. The suspensory apparatus, particularly the proximal sesamoid bones (PSB) was predominantly affected, mostly in the LF. Sixty-nine percent of the PSB fractures occurred biaxially, the medial PSB most commonly affected. PSB fractures were often associated with extensive damage to the flexor tendons and ligaments of the metacarpophalangeal joint. Lateral condylar fractures were more common than medial, and the right forelimb predominantly affected. Significant risk factors for CMI in this study were gender, racing interval, and weight carried. Gender relative to the number of starts had the highest statistical significance (intact males P<0.001 and geldings P=0.010). Intact males were 14.8 times more at risk than females and 5.3 times moreso than geldings. Horses carrying more than 59kg were 3.3 times more at risk of breakdown than horses carrying 54-59kg of weight (P=0.006). Horses with a racing interval of less than one week were approximately three times more at risk than those with longer intervals (P=0.025 and P=0.029 respectively). Statistically insignificant risk factors were racing year, going, distance, racetrack, age, size of field and draw. It is of paramount importance that CMI is strictly monitored and risk factors identified to implement preventative measures to circumvent occurrence of CMI, which may have a negative impact on this important spectator sport. This study provides benchmarks for the racing industry to monitor racetrack fatalities in Gauteng and to evaluate intervention strategies. Copyright / Dissertation (MMedVet)--University of Pretoria, 2009. / Companion Animal Clinical Studies / unrestricted