bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uric acid responses to endurance racing and relationships with performance, plasma biochemistry and metabolic alterations
Authors: CASTEJÓN F. , TRIGO P. , MUÑOZ A. , RIBER C. 
Published: June 2010

SummaryReasons for performing study: There is limited understanding of the uric acid response to endurance races.Objectives: To demonstrate uric acid increments and its relationship to diverse biochemical and performance parameters, in horses subjected to a prolonged effort, with and without presentation of metabolic alterations.Methods: Blood samples were taken from horses the day before, and 5–10 mins after, successfully finishing a 121 km (Assay 1, n = 24) or 164 km endurance race (Assay 2, n = 17), and from 19 animals eliminated by metabolic disorders during several endurance races (Assay 3). Plasma was obtained and determinations of CK, AST, LDH, AP, uric acid (UA), creatinine (Cr), urea, lactate (La) and plasma proteins (PP) carried out. Sex, age, time in competition, average speed and total recovery time were also recorded. Assays 1 and 2 were arithmetically subdivided into 3 groups each in order to categorise time in competition, average speed and total recovery time. Changes among the groups were evaluated with ANOVA and Fisher's PLSD test. Student's paired t test was used to assess pre‐ and post exercise differences. A value of P0.05 was considered significantly different. Pearson correlation coefficient was used to assess the relationship between all the variables and UA increases.Results: Average speed of the sampled horses was significantly higher in Assay 1 compared to Assay 2. However, there were no significant differences in plasma biochemistry values between both groups. The fastest horses showed significantly higher UA levels, compared with the slowest (Assays 1 and 2) and medium horses (Assay 1). The animals with alterations in metabolism had significantly higher UA, CK and PP compared with those that adequately concluded the race. There were significant correlations between UA and CK in Assays 1, 2, and 3 and between UA and PP in Assays 1 and 3. Conclusions: UA rises in horses after a prolonged effort, this increase being higher in animals with metabolic commitment, and in the fastest horses. This increase has a direct correlation with CK.Potential relevance: UA could be useful in the assessment of metabolic response during endurance exercise.
Heart rate responses during acclimation of horses to water treadmill exercise
Authors: NANKERVIS K. J. , WILLIAMS R. J. 
Published: June 2010

SummaryReasons for performing study:The use of water treadmill exercise in horses is popular, although little is known about the physiological responses to this form of exercise. No information exists regarding the time taken to acclimate to water treadmill exercise compared to that of high‐speed treadmill exercise, for both physiological and biomechanical parameters.Objective:To determine heart rate responses during acclimation to water treadmill exercise with and without sedation on first time exposure.Methods:All horses were exercised on a water treadmill at the walk for 15 min once a day for 4 days. Fourteen horses (mean ± s.d. age 9 ± 3.2 years) were assigned randomly toGroup A(sedated) andGroup B(nonsedated). Group A were given 20–30 μg/kg bwt romifidine within 10–15 min prior to the start of the first acclimating run. Acclimation was determined by the time taken to reach a threshold heart rate value.Results:Group A and B reached threshold heart rate values by the 6th minute of the 4th run (72.8 beats/min) and the 6th min of the 3rd run (78.7 beats/min), respectively. No significant difference was found (P>0.05) betweenGroup AandBin the time taken to reach threshold heart rate values. Acclimation to water treadmill exercise requires a minimum of 2 times 15 min nonsedated acclimating runs. Sedation can be used to prevent horses panicking during the first exposure but thereafter does not affect the time taken to acclimate.Potential relevance:Previous experience of water treadmill exercise should be taken into consideration prior to collecting physiological and biomechanical data. Further studies detailing the physiological and biomechanical responses are required prior to making recommendations for the incorporation of this mode of exercise into rehabilitation programmes.
Measurements of right ventricular internal dimensions and their relationships to severity of tricuspid valve regurgitation in National Hunt Thoroughbreds
Authors: HELWEGEN M. M. G. H. J. , YOUNG L. E. , ROGERS K. , WOOD J. L. N. 
Published: June 2010

SummaryReasons for performing study:The effect of tricuspid valve regurgitation (TR) in right ventricular (RV) chamber size has not been reported.Methods:An echocardiographic and auscultation study was conducted on 394 race‐fit National Hunt Thoroughbreds (TBs) in 4 training yards. Auscultation was performed on each horse and audible murmurs of TR graded using a 1–6 scale. Echocardiography was also performed and standard, 2‐dimensional (2D), short (SA) and long axis (LA) images of the RV obtained from a right parasternal location. An m‐mode image was recorded from an SA view of the RV just below the level of the tricuspid valve. Colour flow Doppler (CFD) echocardiography was used to interrogate the tricuspid valve and right atrium. If retrograde flow was visible, representative recordings were also acquired. Severity of TR by CFD was graded using a subjective 1–9 scale. Measurements of RV chamber size in systole and diastole were made from archived 2D, LA, SA and m‐mode images by a single observer unaware of the auscultation and CFD findings. To determine day‐to‐day repeatability of RV measurements from each imaging plane and of TR by CFD, 5 horses were examined on 5 consecutive days using an identical echocardiographic protocol. Images from 30 horses in the original dataset were also measured on a second occasion to determine the intra‐observer repeatability.Results:There were significant positive correlations between the severity of TR by CFD and RV internal diameter from each image plane. In contrast, there were no significant associations between grade of TR by auscultation and any RV dimension. Data also showed that only RV measurements derived from M‐mode images have acceptable intra‐observer repeatability and similarly the M‐mode measurements had the best overall day‐to‐day repeatability.Conclusions and clinical relevance:Data showed that TR assessed by CFD was positively associated with the diastolic and systolic dimensions of the RV, but failed to demonstrate a positive association between the presence of a murmur of TR and RV chamber size. M‐mode and 2D echocardiography provided moderately reliable and repeatable methods for obtaining measurements of RV internal dimensions. M‐mode images provide the most reliable and repeatable measurements, particularly for less experienced operators.
Effects of a specific endothelin‐1Aantagonist on exercise‐induced pulmonary haemorrhage (EIPH) in Thoroughbred horses
Authors: PADILLA D. J. , EPP T. S. , McDONOUGH P. , MARLIN D. J. , ERICKSON H. H. , POOLE D. C. 
Published: June 2010

SummaryReasons for performing study:During high intensity exercise, the very high pulmonary artery pressure (Ppa) experienced by Thoroughbred horses is considered a major factor in the aetiology of exercise‐induced pulmonary haemorrhage (EIPH). Recently, endothelin‐1 (ET‐1), a potent vasoconstrictive hormone, has been found to increase Ppa in horses at rest via binding to its ET‐1Areceptor subtype. In addition, plasma concentrations of ET‐1 are increased in horses during and after high intensity exercise.Hypothesis:If ET‐1 increases Ppa during exercise in the horse, administration of a specific ET‐1Aantagonist would decrease Ppa and therefore EIPH.Methods:Saline (CON) or an ET‐1Areceptor antagonist, TBC3214 (3 mg/kg bwt i.v.; ANTAG) was administered to horses 1 h prior to maximal incremental exercise on a highspeed treadmill. Gas exchange measurements were made breath‐by‐breath and blood samples collected during each 1 min stage to determine blood gases, acid‐base status and cardiac output. EIPH was determined via bronchoalveolar lavage (BAL) ˜30 min after exercise.Results:The time to fatigue, gas exchange and cardiovascular responses were not different between groups (P>0.05). Resting and peak Ppa did not differ significantly between treatments. Most importantly, ANTAG did not decrease EIPH.Conclusions:These results do not support a deterministic role for ET‐1 in the increased Ppa and therefore EIPH, during maximal exercise in the equine athlete.Potential relevance:Treatment with an ET‐1Areceptor antagonist does not appear to be a viable therapeutic intervention in the prevention of EIPH.
Synthesis of proglycogen and macroglycogen in skeletal muscle of Standardbred trotters after intermittent exercise
Authors: BRÖJER J. , HOLM S. , JONASSON R. , HEDENSTRÖM U. , ESSÉN‐GUSTAVSSON B. 
Published: June 2010

SummaryReasons for performing study: The degradation of glycogen and its two forms, proglycogen (PG) and macroglycogen (MG) has been studied in horses performing different types of exercise, but no information is available about the resynthesis of PG and MG after exercise.Objectives: To determine the resynthesis of PG and MG in skeletal muscle after intermittent uphill exercise.Methods: At a training camp 9 well‐trained Standardbred trotters performed a training session comprising a warm‐up period, 7 repeated 500 m bouts of exercise on an uphill slope and a recovery period. Muscle biopsies (m. gluteus medius) for analysis of PG, MG, glucose and glucose‐6‐phosphate were taken at rest, at the end of exercise and 1, 4, 8, 24, 48 and 72 h post exercise. Blood samples for analysis of glucose, lactate and insulin were collected before exercise, immediately after the last bout of exercise and then as for the muscle biopsies.Results: The MG and PG concentration pre‐exercise was 311 ± 47 and 305 ± 55 mmol/kg dwt respectively. The exercise caused a decrease in PG (Δ 63 ± 26 mmol/kg dwt) and MG (Δ 136 ± 68 mmol/kg dwt). Immediately after the last sprint plasma glucose and lactate increased compared to values pre‐exercise. During the first hour post exercise there was a further decrease in MG in 7 out of 9 horses. The rate of glycogen resynthesis during 1–24 h was higher for MG than for PG. The rate of muscle glycogen resynthesis thereafter was slower and did not differ between MG and PG up to 72 h.Conclusion: After repeated bouts of exercise on a slope, resynthesis of glycogen is a slow process and the resynthesis of proglycogen differs from that of macroglycogen. The fraction most depleted during exercise (MG) had no resynthesis during the first hour of recovery but then had the highest rate of resynthesis during the remainder of the first 24 h period.Potential relevance: If the time between exercise sessions during training is too short the recovery period will be inadequate for complete restoration of muscle glycogen.
Recruitment pattern of muscle fibre type during flat and sloped treadmill running in Thoroughbred horses
Authors: ETO D. , YAMANO S. , HIRAGA A. , MIYATA H. 
Published: June 2010

SummaryReasons for performing the study:There is little information about the muscle fibre recruitment pattern during sloped and flat track running in Thoroughbred horses.Objectives:To examine the glycogen depletion pattern of each muscle fibre type during running on a flat and sloped treadmill.Methods:Thirteen Thoroughbred horses (3–9 years old) were used. They were initially subjected to incremental exercise tests on a treadmill at 10 and 0% inclines in each horse to determine running speed at 90 and 60% VO2max. Needle biopsy samples were obtained from the middle gluteal muscle immediately after the running at 90% VO2maxfor 4 min and 60% VO2maxfor 12 min on 10% and 0% inclines treadmill. Four muscle fibre types (Types I, IIA, IIA/IIX, andIIX) were immunohistochemically identified, and optical density of Periodic Acid Schiff staining (OD‐PAS) in each fibre type and the glycogen content of the muscle sample were determined by quantitative histochemical and biochemical procedures.Results:The changes in OD‐PAS showed that the recruitment of all fibre types were identical after each exercise bout, i.e., 4 min running at 90% VO2max(8.4–9.4 m/sec on 10%, 13.9–14.1 m/sec on 0%), and 12 min running at 60% VO2max(5.4–6.0 m/sec on 10%, 7.9–11.2 m/sec on 0%). No significant differences were found in the recruitment patterns of each muscle fibre type between 10 and 0% inclined exercise bouts at the same exercise intensity.Conclusions:The recruitment pattern of muscle fibre type is mainly determined by exercise intensity (%VO2max) and duration, but not by running speed.Potential relevance:The results of this study indicate the possibility that up‐hill running results in the same training effect as faster running on a flat track.
Energetic cost of locomotion on different equine treadmills
Authors: JONES J. H. , OHMURA H. , STANLEY S. D. , HIRAGA A. 
Published: June 2010

SummaryReason for performing study:Human athletes run faster and experience fewer injuries when running on surfaces with a stiffness ‘tuned’ to their bodies. We questioned if the same might be true for horses, and if so, would running on surfaces of different stiffness cause a measurable change in the amount of energy required to move at a given speed?Hypothesis:Different brands of commercial treadmills have pans of unequal stiffness, and this difference would result in different metabolic power requirements to locomote at a given speed.Methods:We tested for differences in stiffness between a Mustang 2200 and a Säto I commercial treadmill by incrementally loading each treadmill near the centre of the pan with fixed weights and measuring the displacement of the pan as weights were added or removed from the pan. We trained six 3‐year‐old Thoroughbreds to run on the 2 treadmills. After 4 months the horses ran with reproducible specific maximum rates of O2consumption (VO2max/kg bwt, 2.62 ± 0.23 (s.d.) mlO2STPD/sec/kg) at 14.2 ± 0.7 (s.d.) m/sec. They were alternately run on the 2 treadmills at identical grade (0.40 ± 0.02%) and speeds (1.83 (walk), 4.0 (trot) and 8.0 (canter) m/sec, all ± 0.03 m/sec) while wearing an open‐flow mask for measurement of VO2.Results:The Mustang treadmill was over 6 times stiffer than the Säto. The VO2/kg bwt increased by approximately 4‐fold over the range of speeds studied on both treadmills. Oxygen consumption was significantly lower at all speeds for the Mustang treadmill compared to the Säto. The fractional difference in energy cost decreased by a factor of 6 with increasing speed, although absolute difference in cost was relatively constant.Conclusions:We suggest it costs less energy for horses to walk, trot or canter on a stiffer treadmill than on a more compliant treadmill, at least within the ranges of stiffness evaluated.Potential relevance:It may be possible to define a substrate stiffness ‘tuned’ to a horse's body enabling maximal energetic economy when running. The differences between treadmills allows more accurate comparisons between physiological studies conducted on treadmills of different stiffness, and might help to identify an ideal track stiffness to reduce locomotor injuries in equine athletes.
Method for quantifying net anaerobic power in exercising horses
Authors: OHMURA H. , HIRAGA A. , JONES J. H. 
Published: June 2010

SummaryReason for performing study:There is no good method for measuring net anaerobic power in exercising horses to allow accurate estimates of total metabolic power.Hypothesis:The increase in VO2maxwhen breathing hyperoxic (HO) gas should be accompanied by a stoichiometrically equal (in terms of ATP turnover, i.e. energy equivalents) decrease in plasma lactate accumulation rate (Mlactate).Methods:Six 3‐year‐old Thoroughbreds were trained on an equine treadmill wearing a semi‐open flow mask for measurement of VO2. After 4 months the horses ran with reproducible specific VO2max(VO2max/kg bwt). The mask design allowed mixing of O2or N2with the inward bias flow of gas so that inspired O2concentration of the horse could be controlled. While the horse breathed either HO (25.1% O2), normoxic (NO, 21% O2) or hypoxic (LO, 19.5% O2) gas, it ran at a speed sufficient to elicit VO2maxin NO while jugular venous blood was drawn at 15 sec intervals over a period of 2 min to determineMlactate.Results:VO2max/kg bwt was not significantly different between LO and NO conditions, and LO data could not be used in the comparison. The VO2max/kg bwt increased from 2.59 ± 0.24 (s.d.) to 2.86 ± 0.24 mlO2(STPD)/sec/kg in NO and HO, respectively, whileMlactatedecreased from 11.5 ± 4.2 to 9.0 ± 3.9 mmol/min as VO2increased.Conclusions:The ratio of ΔMlactateto Δ VO2max/kg bwt suggests thatMlactateof approx 11.1 ± 6.7 mmol/min is associated with net anaerobic power approximately equivalent to 1.0 mlO2(STPD)/sec/kg of aerobic power (20.1 W/kg−1). The high variability in VO2max/kg bwt observed in data from some runs, particularly in LO, suggests that caution must be used when comparing data from the same horse during different runs.Potential relevance:This study provides a tool for estimating net anaerobic power and, more accurately, evaluating total metabolic power of horses exercising at or above their aerobic capacities.
A pattern recognition approach for the quantification of horse and rider interactions
Authors: SCHÖLLHORN W. I. , PEHAM C. , LICKA T. , SCHEIDL M. 
Published: June 2010

SummaryReasons for performing study: Interactions of various systems were investigated in several studies of dynamic systems, but the interactions between horse and rider have not yet been documented. These interactions include the rider's ability to control the horse, adapt to the horse and maintain both participants' body position. An optimum interaction is also adapted to the individual nature of the horse.Objective: To identify rider‐horse interactions by means of artificial neural nets analysing the time‐continuous pattern.Methods: Fourteen horses were measured trotting on hand, and ridden at working trot with a professional and a recreational rider using a 3D high speed video system (120 Hz)1. Angles were calculated after low pass filtering (5–20 Hz). Horse movements were described by 2D angles, angular velocities, and angular accelerations of variables of the right body side: hind and front fetlock, head, back and the summation angle of carpus, elbow, and shoulder, the summation angle of hock, stifle, and hip. Distances between the trajectories of the feature vectors in an N = 11 times 11 Kohonen map were determined and analysed by means of a cluster analysis.Results: Depending on the variables included, both rider specific as well as horse specific movement patterns could be identified. The time courses of the head angle indicate a movement pattern mainly dominated by the rider, whereas the time courses of variables of the hind fetlock and hock in most cases did not show differences between the conditions with, and without, rider. The skill of the professional rider could be documented with a higher adaptation to the horse's movement pattern.Conclusion and potential relevance: The presented time course oriented approach provides a sensitive tool in order to quantify the interaction of rider and horse.
Association of type of sport and performance level with anatomical site of orthopaedic injury diagnosis
Authors: MURRAY R. C. , DYSON S. J. , TRANQUILLE C. , ADAMS V. 
Published: June 2010

SummaryReason for performing study:Although anecdotal reports of increased orthopaedic injury risk in equine sports exist, there is little scientific evidence to support this.Objectives:To test whether horses undertaking a single competitive sport have increased risk of specific injuries compared to those used for general purpose riding (GP); and whether injury type varies with sport category and performance level.Methods:Data from 1069 records of horses undergoing orthopaedic evaluation (1998–2003) and meeting inclusion criteria were reviewed. Sport category (GP, showjumping, dressage, eventing, racing), level (nonelite or elite) and diagnosis were recorded. Effects of sport category and level on probability of a specific diagnosis were assessed using chisquared tests. Logistic regression was used to determine which competitive sports and levels increased risk of injury compared with GP.Results:Overall there was a significant effect of sport category and level on diagnosis (P<0.0001). There was significant difference between anatomical site injured and sport category (P<0.0001); a high risk of forelimb superficial digital flexor tendon injury in elite eventing (P<0.0001) and elite showjumping (P=0.02); distal deep digital flexor tendon (DDFT) injury in elite showjumping (P=0.002); and hindlimb suspensory ligament injury in elite (P<0.0001) and nonelite (P=0.001) dressage. There was a low risk of tarsal injury in elite eventing (P=0.01) and proximal DDFT injury in dressage (P = 0.01).Conclusions:Horses competing in different sports are predisposed to specific injuries; particular sports may increase the risk of injury at certain anatomical sites; and the type and site of injury may reflect the type and level of performance.Potential relevance:These findings could guide clinicians in the diagnosis of sport related injuries.
Abnormal radiographic findings in 865 French Standardbred trotters and their relationship to racing performance
Authors: COUROUCÉ‐MALBLANC A. , LELEU C. , BOUCHILLOUX M. , GEFFROY O. 
Published: June 2010

SummaryReason for performing study:Developmental orthopaedic lesions are commonly found in French Standardbred horses. One of the main questions asked by trainers, owners and veterinarians is what impact these lesions have on the racing career and racing performances of horses.Objectives:To study the prevalence and distribution of developmental orthopaedic lesions in young French Standardbred trotters and to relate them to racing performance.Methods:Feet, fetlock, tarsus and stifle regions were radiographed in 865 two‐year‐old French Standardbred trotters. Abnormal radiographic findings (ARF) were evaluated for 12 anatomical sites identified in these areas, and a severity index given. Performance criteria were: success in qualification for racing, maximal and mean index of trot (ITR), an annual index calculated on the basis of the logarithm of earnings per starts, total earnings at 5 years, placed races compared to starts and longevity of the racing career. Analysis of variance were calculated to study the relationships between racing performance and the number of ARF or the severity index.Results:A total of 363 horses (42.0%) showed ARF. Prevalence of ARF was 18.3% in the plantar aspect of the hind fetlock and 10.6% in the proximal tarsus. Among the total population, 833 horses were considered for performance evaluation, 478 of them were qualified for racing. The number of ARF significantly affected racing longevity. However, the number of ARF did not affect performance categories according to maximal ITR. Concerning distribution of ARF, the number of plantar lesions in the fetlock significantly affected mean ITR. The index of severity did not provide more information for prognosis than the number of ARF.Conclusion:Longevity is the only criteria affected by ARF. When evaluating different sites, only the plantar fetlock region showed a significant relationship with mean ITR.Potential relevance:Number of ARF and radiographic score (RS) affect mean ITR and longevity but do not affect maximal ITR. A horse with a good racing ability will be a good performer but might have a racing career shortened because of orthopaedic problems in relation to developmental orthopaedic lesions.