bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of exercise on blood oxidant/antioxidant markers in Standardbred horses: comparison between treadmill and race track tests
Authors: de MOFFARTS B. , KIRSCHVINK N. , ART T. , PINCEMAIL J. , LEKEUX P. 
Published: June 2010

SummaryReasons for performing study:Interest in establishing oxidant/antioxidant profiles in competition horses is increasing. Earlier studies performed in horses have mainly been performed under laboratory conditions using a treadmill and it is not known to what extent laboratory results of oxidant/antioxidant studies might be transposed to field conditions.Objective:To compare the impact on the blood oxidant/antioxidant status of a standardised exercise test including a run up to fatigue performed on a treadmill (TM) and on a racetrack (RT) in healthy and trained Standardbred horses.Material and methods:During TM and RT tests the following blood antioxidant markers were analysed in jugular venous blood at rest and 15 mins (E15) after an intense bout of exercise: uric acid (UA), ascorbic acid (AA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (reduced: GSH and oxidised: GSSG), glutathione redox ratio (GRR) and protein thiol (PSH). Running time to fatigue (RTF), velocity during the last exercise stage (Vmax), final heart rate (HRfinal) and venous lactic acid (LA) were also recorded.Results:Vmaxwas significantly (P<0.05) higher during the RT, whereas LA was significantly lower. HRfinaland RTF did not differ significantly between TM and RT. Exercise induced a significant increase (R vs. E15) of UA and AA in both tests, whereas GSH and PSH decreased significantly. GPx, SOD, GSSG and GRR remained unchanged. Differences between TM and RT were significant at E15 for UA, AA and PSH.Conclusions:Comparison of oxidant/antioxidant profiles from laboratory and field studies are difficult to standardise and should be interpreted with caution.Potential relevance:For the same RTF and final HR, the TM induced stronger changes in blood lactate and in blood oxidant/antioxidant balance than did RT.
Changes in arterial, mixed venous and intraerythrocytic concentrations of ions in supramaximally exercising horses
Authors: BAYLY W. M. , KINGSTON J. K. , BROWN J. A. , KEEGAN R. D. , GREENE S. A. , SIDES R. H. 
Published: June 2010

SummaryReasons for performing study:Horses experience major perturbations in acid‐base balance during supramaximal exercise. Ion movement in and out of erythrocytes (RBCs) is believed to be important in maintaining acid‐base balance but it is unclear as to the extent to which this happens, nor how it affects single measurements of ion concentrations in arterial and venous blood.Objectives:To clarify the role RBCs play in mitigating perturbations in acid‐base balance during high speed exercise in horses, and to describe associated differences in arterial (a) and mixed venous (v) concentrations of key ions.Methods:Six exercise‐trained Thoroughbreds galloped to fatigue at speeds calculated to have an oxygen demand that was 115% of the VO2max. Blood samples (a and v) were collected pre‐exercise, during warm‐up, at fatigue, and immediately post exercise. Packed cell volume (PCV), pH, PCO2, and plasma concentrations of bicarbonate (HCO3−), chloride (Cl−), sodium (Na+), potassium (K+), and lactate (Lac−) and strong ion difference (SID) were determined, and RBC concentrations of Lac−and electrolytes calculated for each sample. Data were analysed using a 2‐way ANOVA for repeated measures testing for effects of sampling time and site (P<0.05).Results:Plasma and RBC [Cl−] were increased with hypercapnoea and acidaemia. [HCO3−]v was greater than pre‐exercise values at fatigue, although [HCO3−]a was lower. Hyperkalaemia and decreased RBC [K+] were evident at fatigue, as was an increased RBC [Na+]. Plasma [K+] started to decrease as soon as exercise ceased and Na+began to move back onto RBCs in exchange for K+. Concentrations of all measures of Lac−rose from fatigue to post exercise. The SID decreased with exercise and was higher in v at fatigue and post exercise, reflecting the decrease in pH.Conclusions:RBCs act as a repository for lactate, and therefore the increase in PCV facilitates the maintenance of the muscle to plasma Lac−diffusion gradient during exercise.Potential relevance:This serves to keep intramuscular [Lac−] lower than it would otherwise be and, because of the link between Lac−accumulation, pH decrease and the onset of fatigue, may help delay the onset of fatigue.
Plasma concentrations of myeloperoxidase in endurance and 3‐day event horses after a competition
Authors: ART T. , FRANCK T. , GANGL M. , VOTION D. , KOHNEN S. , DEBY‐DUPONT G. , SERTEYN D. 
Published: June 2010

SummaryReason for performing study: In man, exercise of any type has been shown to induce neutrophil degranulation and respiratory burst activity, as well as an increase in plasma myeloperoxidase (MPO), a specific enzyme of neutrophil azurophilic granules with a strong oxidative activity. Until now, it is not known whether this is the same in horses.Objectives: To study whether degranulation of blood neutrophils may be induced by exercise by measuring the total concentration of MPO and assess the possible influence of type of competition on this exercise‐induced adjustment.Methods: Blood was sampled before, and 30 min after, the course, in 9 ponies performing thePhase Dof a national 3‐day event championship (CIC*), and in 7 endurance horses participating at the European endurance championship 2005. White blood cells and granulocytes, total plasma proteins, creatine phosphokinase (CK), and total MPO contents were determined from blood samples. In addition, blood was taken from all ponies and 4 of the endurance horses 5 min after completion of the course to give some idea of the intensity of exercise.Results: The mean blood lactate was 15.8 ± 5.8 mmol/1 after the CIC* and 2.7 ± 0.2 mmol/1 after the 160 km course. Performing both competitions induced a significant increase in CK and MPO. After the endurance course, the number of granulocytes significantly increased. Whilst there was no significant correlation between the measurements in CIC* ponies, MPO was significantly correlated with granulocyte count (r2= 0.776) and CK (r2= 0.586) in endurance horses.Conclusions: Intense exercise induces an activation of blood granulocytes, with degranulation of neutrophils and release of MPO. The plasmatic MPO concentration after endurance was higher than the values reported in some inflammatory pathological conditions.Potential relevance: This phenomenon may partly contribute to the occurrence of an exercise‐induced oxidative stress and to the alteration of muscular membrane permeability. Further studies should be conducted to assess the possible relationship between MPO concentration and markers of oxidative stress in performance horses.
Myosin heavy chain fibre type composition in foals: analyses at the mRNA and protein level
Authors: EIZEMA K. , Van der WAL D. E. , Van den BURG M. M. M. , DINGBOOM E. G. , EVERTS M. E. 
Published: June 2010

SummaryReasons for performing study:An optimal developed musculoskeletal system is vital for the performance of the horse. Previously, we showed that in them. gluteus mediusfrom adult untrained horses, identical mRNA and protein expression patterns were found in the majority of fibres. However, co‐expression of IIa and IId/x myosin heavy chain (MyHC) was substantially more common at the protein than at the mRNA level, suggesting a transcriptionally controlled fine‐tuning of these 2 genes.Objective:To analyse the MyHC transcripts and proteins (including the cardiac alpha isoform) in the same muscle during post natal development when the muscle is adapting to movement and load.Methods:Biopsies were taken from them. gluteus mediusof 2 Dutch Warmblood foals at 0, 2, 4, 22 and 48 weeks of age. mRNA was compared to protein expression on a fibre‐to‐fibre basis usingin situhybridisation and immunofluorescence. The MyHC slow (I), alpha, IIa and IId/x isoforms were analysed.Results:At all ages the expression of the mRNA and protein MyHC isoforms was almost identical. Surprisingly, co‐expression of the IIad isoform was also detected at the mRNA level especially early in life. The transcript of the alpha isoform was only detectable at young age, indicating silencing of the gene around birth.Conclusion:During the first year of life, MyHCs are continuously adapting at the mRNA and protein level. Additionally, the regulation of hybrid fibres is different from that in adult fibres.Potential relevance:We postulate that interfering in this process by e.g. early training will be levelled out by the maturation of the muscle.
Prevalence of polysaccharide storage myopathy in horses with neuromuscular disorders
Authors: McCUE M. E. , RIBEIRO W. P. , VALBERG S. J. 
Published: June 2010

SummaryReasons for performing study:Controversy exists as to the prevalence of polysaccharide storage myopathy (PSSM) in breeds of horses and its impact on performance.Objectives:To determine 1) the prevalence of PSSM in horses that presented with a neuromuscular disorder, as well as breed, sex and age distributions and clinical signs 2) effect of diagnostic criteria on prevalence, breed distribution and age of horses diagnosed with PSSM.Methods:Fresh frozen biopsies (n = 1426) submitted to the Neuromuscular Diagnostic Laboratory at the University of Minnesota were searched to identify horses diagnosed with PSSM. Horses with and without histological evidence of PSSM were compared. Biopsies were classified asGrade 1, containing aggregates of granular glycogen orGrade 2, containing periodic acid Schiff's (PAS) positive inclusions, traditionally resistant to amylase digestion.Results:Horses (n = 572: 40.1%) were identified with PSSM, of which 62.9% were Quarter Horse related breeds (QHR), 11.5% Draught breeds (DB) and 8.9% Warmblood breeds (WB). Exertional rhabdomyolysis was more prevalent in QHR than DB and WB, whereas QHR were less likely to have muscle atrophy compared to DB. QHR were less likely to have gait abnormalities than DB and WB. The highest within breed prevalence of PSSM was in DB at 63/116, WB 58/111 and QHR 360/753. Exclusion ofGrade 1criteria decreased the overall prevalence of PSSM to 21.7% of biopsy submissions, and decreased the within breed prevalence in each breed category. The within breed prevalence decreased most substantially in the breeds less commonly diagnosed with PSSM, Thoroughbreds (4.5%) and Arabians (2.5%).Conclusion:PSSM is a common cause of neuromuscular disease in QHR, DB and WB related breeds. Inclusion of granular glycogen as the sole diagnostic criterion may increase the sensitivity of this diagnostic test, but conversely it may decrease the specificity of the diagnosis resulting in the inclusion of horses of Thoroughbred, Arabian and other breeds.Potential relevance:PSSM is an important differential diagnosis for QHR, WB and DB presenting with signs of rhabdomyolysis, gait abnormalities and muscle atrophy.
Muscle, tendon, and somatotropin responses to the restriction of muscle blood flow induced by KAATSU‐walk training
Authors: ABE T. , KEARNS C. F. , FILHO H. C. MANSO , SATO Y. , McKEEVER K. H. 
Published: June 2010

SummaryObjective:The efficacy of KAATSU training has been demonstrated in human athletes, both as a therapeutic method as well as a training aid. The purpose of this study was to investigate the effects of slow walk training combined with restriction of muscle blood flow (KAATSU) on muscle and tendon size.Methods:Six healthy, unfit Standardbred mares performed walking (240 m/min for 10 min and then 5 min recovery) with KAATSU, and 6 mares performed walking without KAATSU. A specially designed elastic cuff1was placed at the most proximal position of the forelegs and inflated to a pressure of 200–230 mmHg throughout the walking and recovery sessions. The training was conducted once a day, 6 days/week for 2 weeks. Skeletal muscle thickness and tendon thickness were measured using B‐mode ultrasound at baseline and after 2 weeks of training. Venous blood samples were obtained before the first acute exercise and 5, 15 and 60 min afterwards. Serum somatotropin concentration was determined using a commercially available equine‐specific ELISA kit.Results:The acute increase in plasma somatotropin was 40% greater (P<0.05) in the KAATSU‐walk group than in the Control‐walk group 5 min after exercise and remained elevated (P<0.05) at 15 and 60 min post exercise compared with the Control‐walk group. After 2 weeks of training, muscle thickness increased (P<0.05) 3.5% in the KAATSU‐walk group but did not change in the Control‐walk group (0.7%). Tendon thickness did not change (P>0.05) in either group.Conclusions:These data demonstrate that KAATSU training can induce muscle hypertrophy in horses and suggest that KAATSU training may provide significant therapeutic/rehabilitative value in horses, as has been shown in man.
Effect of head and neck position on vertical ground reaction forces and interlimb coordination in the dressage horse ridden at walk and trot on a treadmill
Authors: WEISHAUPT M. A. , WIESTNER T. , von PEINEN K. , WALDERN N. , ROEPSTORFF L. , Van WEEREN R. , MEYER H. , JOHNSTON C. 
Published: June 2010

SummaryReasons for performing study:Little is known in quantitative terms about the influence of different head‐neck positions (HNPs) on the loading pattern of the locomotor apparatus. Therefore it is difficult to predict whether a specific riding technique is beneficial for the horse or if it may increase the risk for injury.Objective:To improve the understanding of forelimb‐hindlimb balance and its underlying temporal changes in relation to different head and neck positions.Methods:Vertical ground reaction force and time parameters of each limb were measured in 7 high level dressage horses while being ridden at walk and trot on an instrumented treadmill in 6 predetermined HNPs: HNP1 ‐ free, unrestrained with loose reins; HNP2 ‐ neck raised, bridge of the nose in front of the vertical; HNP3 ‐ neck raised, bridge of the nose behind the vertical; HNP4 ‐ neck lowered and flexed, bridge of the nose considerably behind the vertical; HNP5 ‐ neck extremely elevated and bridge of the nose considerably in front of the vertical; HNP6 ‐ neck and head extended forward and downward. Positions were judged by a qualified dressage judge. HNPs were assessed by comparing the data to a velocity‐matched reference HNP (HNP2). Differences were tested using pairedttest or Wilcoxon signed rank test (P<0.05).Results:At the walk, stride duration and overreach distance increased in HNP1, but decreased in HNP3 and HNP5. Stride impulse was shifted to the forehand in HNP1 and HNP6, but shifted to the hindquarters in HNP5. At the trot, stride duration increased in HNP4 and HNP5. Overreach distance was shorter in HNP4. Stride impulse shifted to the hindquarters in HNP5. In HNP1 peak forces decreased in the forelimbs; in HNP5 peak forces increased in fore‐ and hindlimbs.Conclusions:HNP5 had the biggest impact on limb timing and load distribution and behaved inversely to HNP1 and HNP6. Shortening of forelimb stance duration in HNP5 increased peak forces although the percentage of stride impulse carried by the forelimbs decreased.Potential relevance:An extremely high HNP affects functionality much more than an extremely low neck.
Functional anatomy of the caudal thoracolumbar and lumbosacral spine in the horse
Authors: STUBBS N. C. , HODGES P. W. , JEFFCOTT L. B. , COWIN G. , HODGSON D. R. , McGOWAN C. M. 
Published: June 2010

SummaryReasons for performing study:Research in spinal biomechanics and functional anatomy has advanced back pain research in man. Yet, despite the performance limiting nature of back pain in horses, there are few data for the equine spine.Objectives:To describe aspects of functional anatomy of the equine thoracolumbar and lumbosacral (LS) spine and potential effects on performance.Methods:The first study investigated variations in LS vertebral formula bypost mortemexamination of 120 horses. Midline vertebral transection was carried out on 65 Thoroughbred (TB), 24 Standardbred (SB) and 31 other breeds. The second study investigated morphology and biomechanics of the deep stabilising epaxial muscles of 13 horses using MRI (n=3), anatomical dissection (n=11) and biomechanical analysis (n = 6). The spinous process angular orientation relative to the vertebral body, was analysed at vertebrae T13, T18, L3, L5, L6 and S1.Results:LS variations were found in 33.3% of the total group, 40.0% TB and 45.2% others, but 0% SB. Sacralisation of lumbar vertebra (L) 6 with LS motion between L5 and L6 occurred in 32.3% TB and 29.0% others. Five segmentalmultifidusfascicles were identified originating from spinous processes and vertebral laminae running craniocaudally onto the mammillary processes and lateral border of the sacrum, crossing between 1–5 intervertebral discs.Sacrocaudalis dorsalis(SCD)lateralismuscle was an extension ofmultifidusfrom L4, L5 and L6 depending on the vertebral formula whereas SCD medialismmoriginated from S3. Both inserted on caudal vertebrae. Based on the location and direction of fibres, the principal action of the deep epaxial muscles was dorsoventral sagittal rotation. This action was dependent on vertebral spinous process/body orientation. We hypothesise that equinemultifidusand SCDlateralismuscles act as caudal sagittal rotators of their vertebra of origin, as is the case in man, allowing dynamic stabilisation during dorsoventral motion.Conclusion:Equinemultifidusanatomy and function are comparable to that of man. The high prevalence of anatomical variations in the LS spine may affect maximal dorsoventral motion, the stability of the LS joint and, therefore, have consequences for athletic performance. Further studies of these structures are warranted in appropriately selected poorly performing horses.
The effect of head and neck position on the thoracolumbar kinematics in the unridden horse
Authors: ÁLVAREZ C. B. GÓMEZ , RHODIN M. , BOBBERT M. F. , MEYER H. , WEISHAUPT M. A. , JOHNSTON C. , Van WEEREN P. R. 
Published: June 2010

SummaryReasons for performing study:In many equestrian activities a specific position of head and/or neck is required that is dissimilar to the natural position. There is controversy about the effects of these positions on locomotion pattern, but few quantitative data are available.Objectives:To quantify the effects of 5 different head and neck positions on thoracolumbar kinematics of the horse.Methods:Kinematics of 7 high level dressage horses were measured walking and trotting on an instrumented treadmill with the head and neck in the following positions: HNP2=neck raised, bridge of the nose in front of the vertical; HNP3=as HNP2 with bridge of the nose behind the vertical; HNP4=head and neck lowered, nose behind the vertical; HNP5=head and neck in extreme high position; HNP6 = head and neck forward and downward. HNP1 was a speed‐matched control (head and neck unrestrained).Results:The head and neck positions affected only the flexion‐extension motion. The positions in which the neck was extended (HNP2, 3, 5) increased extension in the anterior thoracic region, but increased flexion in the posterior thoracic and lumbar region. For HNP4 the pattern was the opposite. Positions 2, 3 and 5 reduced the flexion‐extension range of motion (ROM) while HNP4 increased it. HNP5 was the only position that negatively affected intravertebral pattern symmetry and reduced hindlimb protraction. The stride length was significantly reduced at walk in positions 2, 3, 4 and 5.Conclusions:There is a significant influence of head/neck position on back kinematics. Elevated head and neck induce extension in the thoracic region and flexion in the lumbar region; besides reducing the sagittal range of motion. Lowered head and neck produces the opposite. A very high position of the head and neck seems to disturb normal kinematics.Potential relevance:This study provides quantitative data on the effect of head/neck positions on thoracolumbar motion and may help in discussions on the ethical acceptability of some training methods.
Head and body centre of mass movement in horses trotting on a circular path
Authors: CLAYTON H. M. , SHA D. H. 
Published: June 2010

SummaryMcPhail Equine Performance Centre, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan 48824, USA.Reasons for performing study:Horses are often worked along a circular trajectory but the mechanics of turning have not been reported.Objective:To develop a methodology for kinematic analysis of horses during circling and to report preliminary findings describing movements of the total body centre of mass (COMbody).Methods:Seventy‐five skin markers, distributed over the head, neck, trunk and limbs of 5 sound horses, were tracked in a global coordinate system at 120 Hz as the horses trotted around a small circle. Based on segmental inertial data, 3D positions of the segmental centres of mass and COMbodywere calculated. Movements of COMbodywere measured relative to the cylindrical vertical plane, the radius of which was defined by a marker overlying the sixteenth thoracic vertebra.Results:During trotting, COMbodywas high at the start and end of the diagonal stance phases and low in midstance. All horses leaned to the inside of the circle, with a tilt angle of mean ± s.d. 14.8 ± 2.8° during the entire stride. In the transverse direction, COMbodyswung from side to side reaching its most inward position around the time of contact of the inside forelimb and its most outward position around the time of contact of the outside forelimb. The centre of mass of the head and neck segments (COMhead/neck) had a symmetrical, double sinusoidal pattern in the vertical direction. All horses had the same motion pattern for COMhead/neckin the transverse direction but the mean position relative to the circle line varied between horses.Conclusions:Horses lean to the inside when turning around a small circle. COMhead/neckand COMbodyshowed 2 vertical oscillations in each stride, whereas there was a single mediolateral excursion that was not symmetrical to the inside and outside of the circle line.Potential relevance:This study provides a first step toward understanding the mechanics of locomotion during turning, which has implications in the aetiology of injuries, the response to lungeing as a diagnostic technique and the incorporation of circles into rehabilitation exercises.