Journal Articles
Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915
Browse
48 results
Search Results
Item Turf track surface interaction with speed and musculoskeletal injury risk in Thoroughbred racehorses(John Wiley and Sons Ltd on behalf of EVJ Ltd, 2025-07-24) Legg KA; Gibson MJ; Gee EK; Rogers CWBackground: Injury modelling based on changes in speed and stride characteristics of racehorses has become a primary industry focus for the Thoroughbred racing industry. However, speed and stride characteristics are strongly associated with track condition; therefore, reliable quantification of surface variables for use in future models is imperative. Objectives: This study aimed to understand the interaction of objective turf track condition score (TCS) measurement with racing speed and injury in flat racing Thoroughbred horses. Study Design: Retrospective time series analysis. Methods: Race-day data from 16 flat racing seasons (2008/9–2023/24, n = 40,824 races) were used to compare monthly TCS (based on penetrometer measurements), the coefficient of variability (CV) for TCS, race speed (over the final 600 m) and the number of race starts. Injury data from 7 seasons (2015–17, 2019–24) were used to calculate the monthly incidence rate (IR per 1000 race starts) of musculoskeletal injury (MSI). A mixed effects linear model was used to assess the relationship between speed, TCS, race distance and horse rating. Results: Race starts (n = 437,506), TCS and speed showed strong seasonal fluctuations, with more starts, lower and more variable TCS (4, IQR 3–5, CV = 0.44) and higher race speed (16.7 m/s, IQR 16.1–17.2) in summer compared with winter (TCS 10, IQR 8–10, CV = 0.22, p < 0.001 and speed 15.1 m/s, IQR 14.3–15.8, p < 0.001). Race speed had a strong negative quadratic relationship with TCS (β₂ = −0.03, p < 0.001), a negative linear correlation with race distance and was positively correlated with horse rating. There were 433 MSI (IR = 2.22, 95% CI 2.20–2.44), with an immediate (0 lag time) positive association with seasonal changes in TCS (r = −0.28). Main Limitations: Low monthly numbers of MSI constrained analysis of interaction with track variables. Conclusions: TCS provides a reliable quantitative measure of track condition which could be used to refine future models of injury risk in racing Thoroughbreds.Item Insights into the pathogenesis of catastrophic spontaneous humeral fractures in first-lactation dairy cows(CSIRO Publishing, Australia, 2025-05-06) Wehrle-Martinez AS; Lawrence KE; Back PJ; Rogers CW; Gibson MJ; Dittmer KE; Eastwood CSpontaneous humeral fractures in first-lactation dairy cows have introduced significant challenges to the dairy industry in New Zealand, impacting animal welfare, farm economics, and veterinary practices. This review synthesizes current knowledge on the pathogenesis of these fractures and identifies potential key risk factors. The majority of bones from affected first-lactation dairy cows have osteoporosis, which is associated with inadequate bone formation and increased bone resorption. In addition, low total collagen content in bones from most affected dairy cows supports the hypothesis that inadequate bone formation is an important risk factor associated with humeral fractures in these cows. Spectroscopic analyses further confirmed a significant reduction in bone quality and strength. Novel findings suggest that low liver copper concentration in many of the affected cows' results from the mobilisation of copper to the bone. Although limited, the accumulated evidence suggests that to mitigate the incidence of catastrophic fractures, adequate nutrition (especially protein-energy) should be supplied during important growth periods. While significant progress has been made in understanding the cause of these fractures, many uncertainties and areas requiring further research remain.Item The genetic parameters of racing success and longevity in the New Zealand Thoroughbred racing industry(Taylor and Francis Group on behalf of the Royal Society Te Apārangi, New Zealand, 2025-04-23) Chin YY; Sneddon NW; Gibson MJ; Legg KA; Gee EK; Rogers CW; Handcock RWithin the Thoroughbred industry, individual success can be measured with races and prize money won. At an industry level, there is a requirement for horses to be able to race from a young age and have a sustained injury-free career. Therefore, the variance components of such traits were investigated within ASReml for 26,920 New Zealand Thoroughbred racehorses. Age at first competitive high-speed event (trial or race start) had high heritability (h2= 0.52 ± 0.02), and an inverse genetic correlation with career earnings (−0.40 ± 0.05) and number of wins (−0.35 ± 0.06). Career earnings (h2 = 0.24 ± 0.02) had positive genetic and phenotypic correlations (0.59 ± 0.004) with career length, implying that racing success could be a useful selection proxy for career length. Horses that started earlier had longer career length (−0.21 ± 0.07,–0.18 ± 0.01). The low heritability of career length (0.11 ± 0.01) reflects considerable environmental influence on this trait, reinforcing the importance of early training and exercise in increasing career length. Therefore, the optimal strategy is a selection programme focusing on racing success, which improves commercial appeal and is genetically correlated with longevity. A training and racing programme that encourage an early competitive high-speed event would optimise the phenotypic development of the musculoskeletal system and reduce injury risk.Item Relationship between experience and head kinematics in race riding jockeys(Springer Nature Limited, London, 2025-04-26) Legg KA; Cochrane DJ; Gee EK; Chin Y-Y; Rogers CWThoroughbred race-riding requires jockeys to attenuate horse movement and maintain postural stability whilst galloping at high speeds. This study aimed to investigate the head movement of jockeys in relation to race-riding experience. Accelerometer and heart rate data were collected from twelve apprentice and two senior jockeys during 85 exercise rides and 82 trial rides. Mean head displacements were determined for each jockey by double integrating the filtered acceleration data. A mixed effect multivariable linear regression model was used to investigate the relationship between jockey experience, physiological variables and head kinematics. The median (IQR) head displacement was higher for exercise riding (0.12 m, 0.09–0.14 m) than trial riding (0.06 m, 0.05–0.09 m). Jockey head displacement decreased with increasing speed of the horse (p < 0.001) and greater jockey experience (p = 0.007). Higher exercise load had a greater effect on head displacement with less experienced jockey’s (p = 0.02). The effect of speed was lower for trial riding than exercise riding (p < 0.001). More experienced jockeys had a greater ability to attenuate horse oscillation than inexperienced jockeys. This ability became more pronounced at higher exercise loads, reflecting a higher level of physical fitness and riding skill level. Measurement of jockey head displacement may provide a simple measure of assessing jockey race-riding ability or fitness.Item The Relationship Between Stature and Live Weight of Dairy Cows Between Birth and Maturity(MDPI (Base, Switzerland), 2025-03) Gibson MJ; Sneddon NW; Rogers CW; Back PJ; Dittmer KE; Martín NP; Bezerra LR; Lancaster PLactational and reproductive performance are strongly associated with cow live weight and capacity. However, there are limited data published describing capacity (thoracic) growth and the prediction of final stature and capacity from measurements at birth. Therefore, the aim of this study was to examine the relationship between stature and live weight of female dairy cattle between birth and maturity. Forty dairy cows, with records of stature and capacity from birth up until two years of age, underwent follow-up measurements for live weight, height at withers, wither-rump length, girth circumference and leg length on four occasions between 42 and 52 months of age. Measures of wither height, leg length and wither rump length at fourth mating had the strongest association with measures at birth (R2 > 0.90) compared to girth and live weight (R2 = 0.88 and 0.82, respectively). The weaker association between birth and maturity measures for girth is likely a reflection of the stronger relationship with live weight resulting in a later maturity (approximately 810 days) compared to linear measures such as height (approximately 730 days). Therefore, to maximise capacity, adequate nutrition is required until approximately 810 days of age when capacity growth is most sensitive to environmental input.Item The association between fluoride concentrations and spontaneous humeral fracture in first-lactation dairy cows: results from two New Zealand studies(Taylor and Francis Group, 2024-11-17) Wehrle-Martinez A; Dittmer KE; Back PJ; Rogers CW; Weston JF; Jeyakumar P; Pereira RV; Poppenga R; Taylor HS; Lawrence KEAIM: To assess whether the fluoride concentration in the humeri of first-lactation, 2-year-old dairy cows with a spontaneous humeral fracture is significantly different from that of first-lactation, 2-year-old dairy cows without a humeral fracture. METHODS: Two studies were conducted, the first with nine bone samples from 2-year-old, first-calving dairy cows with a humeral fracture (all from the Waikato region) age-matched with seven control bone samples from the Waikato, Bay of Plenty and Manawatū-Whanganui regions. The second study used 26 bone samples from 2-year-old, first-lactation dairy cows with a humeral fracture (from the Otago, Canterbury, Southland, West Coast, Waikato and Manawatū-Whanganui regions) age-matched with 14 control bone samples (all from the Manawatū-Whanganui region or unknown). Control bone samples were from first-lactation, 2-year-old dairy cows that did not have humeral fractures. Bone fluoride concentration was quantified for all samples. RESULTS: The median fluoride concentration of humeri from first-lactation, 2-year-old dairy cows with a humeral fracture was significantly higher than humeri from unaffected control cows in both studies. In Study 1, the median bone fluoride concentration was 599 (IQR 562.7-763.5) mg/kg from case cows and 296.6 (IQR: 191.2-391.7) mg/kg from control cows (p < 0.001), and in Study 2 the median bone fluoride concentration from case and control cows was 415 (IQR: 312.5-515) mg/kg and 290 (IQR: 262.5-410) mg/kg (p = 0.04) respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Although there are limitations to this study due to the unbalanced regional distribution of cases and controls, the results indicate that sub-clinical fluoride toxicosis may be linked to spontaneous humeral fractures in first-lactation dairy cows in New Zealand. Further research is required to determine if bone fluoride concentrations play a role in the pathogenesis of these fractures.Item A threshold model to determine the association between race rides and fall risk for early career (apprentice) jockeys.(Elsevier B.V., 2024-10-31) Legg KA; Cochrane DJ; Gee EK; Rogers CWObjectives To identify descriptors associated with success in apprentice jockeys and to determine optimum numbers of jockeys for safer race riding. Design Retrospective cohort study. Methods Incidence-rates for jockey falls and success (wins per 1,000 race-starts), time and number of races spent at different apprentice levels were calculated for 807 apprentice and professional jockeys over 19 years of Thoroughbred flat racing in New Zealand (n = 524,551 race-starts). Survival analysis was used to compare career progression for jockeys that fell and those that did not, and individual seasonal fall incidence-rates were modelled. Results Apprentices had the highest fall incidence-rate in their first year of race riding (2.4, interquartile range 1.7–3.2 vs 1.1, interquartile range 1.0–1.2, p < 0.05) and a lower success incidence-rate compared to non-apprentice jockeys (71, interquartile range 67–75 vs 97 interquartile range 96–98, p < 0.05). Jockeys who fell during their apprenticeship rode in more race rides to progress towards professional status than those who did not. There was an inverse power relationship between fall incidence-rate and race rides per season for jockeys, with the inflection point at 33 rides per season. Half (48 %) of the jockeys rode fewer than 33 rides per season. Conclusions There is a surplus number of jockeys, riding at high fall risk, produced than is required by the number of race riding opportunities. Greater investment into the fitness, education and selection of a smaller cohort of dedicated apprentices, may be beneficial to reduce the risk of early career fall or injury in jockeys and requires further investigation.Item Incidence and risk factors for limb fracture in greyhound racing in Western Australia(John Wiley and Sons Australia, Ltd on behalf of Australian Veterinary Association, 2024-10-04) Gibson MJ; Legg KA; Gee EK; Smet A; Medd J; McMullen C; Auld L; Rogers CWIdentification of risk factors for race day injury can improve greyhound welfare. Race day fractures are the most significant injury event and have the greatest negative impact on dog welfare and the industry's social license to operate. This study aimed to describe the incidence and risk factors for race-related fractures in greyhounds racing in Western Australia. Electronic extracts describing race level data and race day injuries were provided by Racing and Wagering Western Australia (RWWA). The incidence rate (IR) of fractures for all greyhound race starts in Western Australia from 1 January 2017-31/12/2023 was calculated per 1000 starts. Univariable and multivariable models using Poisson regression were used to calculate the IR ratio of fracture type based on race and greyhound-level factors. There were 198,008 racing starts and 662 (n = 643, 97.1% involving the limbs) fractures resulting in an IR of 3.3 fractures per 1000 starts (95%CI 3.1-3.6). Greyhounds that had an injury in their previous race were 2.3 times (95%CI1.4-4.3) more likely to have a forelimb fracture than greyhounds that did not have an injury (P = 0.013). The risk of tarsal bone fracture was greater in greyhounds older than 30 months and greyhounds that had not raced in the previous 15 days. Risk factors for fractures in the forelimb were associated with trauma after interference or dog collisions, whereas tarsal fractures were associated with strain and cyclic loading from race training/racing. Changes to racing structure, rules and policies based on these risk factors may help to reduce fracture incidence in racing greyhounds.Item Comparison of Citrated Whole Blood to Native Whole Blood for Coagulation Testing Using the Viscoelastic Coagulation Monitor (VCM Vet™) in Horses.(MDPI (Basel, Switzerland), 2024-10-08) Vokes JR; Lovett AL; de Kantzow MC; Rogers CW; Wilkins PA; Sykes BW; Mendoza García FViscoelastic monitoring of horse coagulation is increasing due to its advantages over traditional coagulation testing. The use of a point-of-care viscoelastic coagulation monitor (VCM Vet™) has been validated for use in horses using native whole blood (NWB) but has not been assessed using citrated whole blood (CWB), a technique that might have advantages in practicality and precision. Blood was collected from 70 horses, tested in duplicate immediately using NWB (T0), and stored at room temperature as CWB for testing in duplicate at 1 (T1) and 4 (T4) hours after venipuncture for comparison to NWB. Of these horses, 20 were classified as clinically healthy and used to determine reference intervals for CWB at 1 and 4 h post-collection. There were clinically relevant differences in all measured viscoelastic parameters of CWB compared to NWB meaning that they cannot be used interchangeably. These differences were not consistent at T1 and T4 meaning the resting time of CWB influences the results and should be kept consistent. The use of CWB in this study also resulted in more machine errors when compared to NWB resulting in measurements that might not be interpretable.Item The intrauterine effects of a maternal winter diet of either kale or fodder beet on measures of calf stature and bone morphology at birth(Taylor and Francis Group, 2024-10-09) Gibson MJ; Rogers CW; Back PJ; Dittmer KE; Wehrle-Martinez A; Dalley DE; Woods RRFodder beet and kale are commonly used winter crops in New Zealand dairy and dairy support farm systems. Fodder beet (FB) is known to have lower crude protein, phosphorus and calcium content compared to kale. The intrauterine effects of feeding FB during late pregnancy on bone growth and development in calves requires attention. This study aimed to examine the intrauterine effects of a maternal diet of either kale or FB on measures of calf stature and bone morphology at birth. In winters 2019 and 2020, two herds of pregnant Friesian ×Jersey cows were fed either kale (2019, 2020 n = 20) or FB (2019, 2020 n = 20) supplemented with pasture baleage. Calves born from these mobs were euthanised within ten days of birth and a forelimb and section of rib including the costochondral junction were harvested for peripheral quantitative computed tomography and histological analysis. Calves from the FB treatment had reduced bone density and strength compared to calves from the kale treatment (p <.05). The effect of a nutritional deficit on bone morphology at birth emphasises the importance of sufficient nutrition in pre-calving diets. Future research is required to examine the long-term impact of dam undernutrition on calf growth and production.