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Author Young, L.E.; Rogers, K.; Wood, J.L.N.
Title Left ventricular size and systolic function in Thoroughbred racehorses and their relationships to race performance Type Journal Article
Year 2005 Publication Journal of Applied Physiology (Bethesda, Md. : 1985) Abbreviated Journal J Appl Physiol
Volume 99 Issue 4 Pages 1278-1285
Keywords *Adaptation, Physiological; Aging/physiology; Animal Husbandry; Animals; *Echocardiography; Female; Heart/*physiology; Heart Ventricles; Horses/*physiology; Male; *Physical Conditioning, Animal; Running/*physiology; Stroke Volume; Systole; Task Performance and Analysis
Abstract Cardiac morphology in human athletes is known to differ, depending on the sports-specific endurance component of their events, whereas anecdotes abound about superlative athletes with large hearts. As the heart determines stroke volume and maximum O(2) uptake in mammals, we undertook a study to test the hypothesis that the morphology of the equine heart would differ between trained horses, depending on race type, and that left ventricular size would be greatest in elite performers. Echocardiography was performed in 482 race-fit Thoroughbreds engaged in either flat (1,000-2,500 m) or jump racing (3,200-6,400 m). Body weight and sex-adjusted measures of left ventricular size were largest in horses engaged in jump racing over fixed fences, compared with horses running shorter distances on the flat (range 8-16%). The observed differences in cardiac morphologies suggest that subtle differences in training and competition result in cardiac adaptations that are appropriate to the endurance component of the horses' event. Derived left ventricular mass was strongly associated with published rating (quality) in horses racing over longer distances in jump races (P < or = 0.001), but less so for horses in flat races. Rather, left ventricular ejection fraction and left ventricular mass combined were positively associated with race rating in older flat racehorses running over sprint (<1,408 m) and longer distances (>1,408 m), explaining 25-35% of overall variation in performance, as well as being closely associated with performance in longer races over jumps (23%). These data provide the first direct evidence that cardiac size influences athletic performance in a group of mammalian running athletes.
Address Centre for Equine Studies, Animal Health Trust, Newmarket, Suffolk, UK. lesley.young@aht.org.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 8750-7587 ISBN Medium
Area Expedition Conference
Notes PMID:15920096 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 3768
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Author Rollot, Y.; Lecuyer, E.; Chateau, H.; Crevier-Denoix, N.
Title Development of a 3D model of the equine distal forelimb and of a GRF shoe for noninvasive determination of in vivo tendon and ligament loads and strains Type Journal Article
Year 2004 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J
Volume 36 Issue 8 Pages 677-682
Keywords Animals; Biomechanics; Floors and Floorcoverings; Forelimb/*physiology/ultrasonography; Gait/physiology; Horses/*physiology; Image Processing, Computer-Assisted; Imaging, Three-Dimensional/methods/*veterinary; Ligaments, Articular/*physiology; Locomotion/*physiology; Models, Biological; Shoes; Tendons/*physiology; Toe Joint/physiology/ultrasonography
Abstract REASONS FOR PERFORMING STUDY: As critical locomotion events (e.g. high-speed and impacts during racing, jump landing) may contribute to tendinopathies, in vivo recording of gaits kinematic and dynamic parameters is essential for 3D reconstruction and analysis. OBJECTIVE: To propose a 3D model of the forelimb and a ground reaction force recording shoe (GRF-S) for noninvasively quantifying tendon and ligament loads and strains. METHODS: Bony segments trajectories of forelimbs placed under a power press were recorded using triads of ultrasonic kinematic markers linked to the bones. Compression cycles (from 500-6000 N) were applied for different hoof orientations. Locations of tendon and ligament insertions were recorded with regard to the triads. The GRF-S recorded GRF over the hoof wall and used four 3-axis force sensors sandwiched between a support shoe and the shoe to be tested. RESULTS: Validation of the model by comparing calculated and measured superficial digital flexor tendon strains, and evaluation of the role of proximal interphalangeal joint in straight sesamoidean ligament and oblique sesamoidean ligament strains, were successfully achieved. Objective comparisons of the 3 components of GRF over the hoof for soft and hard grounds could be recorded, where the s.d. of GRF norm was more important on hard ground at walk and trot. CONCLUSIONS: Soft grounds (sand and rubber) dissipate energy by lowering GRF amplitude and diminish bounces and vibrations at impact. At comparable speed, stance phase was longer on soft sand ground. POTENTIAL RELEVANCE: The conjugate use of the GRF-S and the numerical model would help to quantify and analyse ground/shoe combination on comfort, propulsion efficiency or lameness recovery.
Address UMR INRA-ENVA de Biomecanique et Pathologie Locomotrice du Cheval, Ecole Nationale Veterinaire d'Alfort, 7, Avenue du General de Gaulle, 94704 Maisons-Alfort, France
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0425-1644 ISBN Medium
Area Expedition Conference
Notes PMID:15656495 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 3769
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Author Santamaria, S.; Bobbert, M.E.; Back, W.; Barneveld, A.; van Weeren, P.R.
Title Variation in free jumping technique within and among horses with little experience in show jumping Type Journal Article
Year 2004 Publication American Journal of Veterinary Research Abbreviated Journal Am J Vet Res
Volume 65 Issue 7 Pages 938-944
Keywords *Acceleration; Analysis of Variance; Animals; Biomechanics; Forelimb/physiology; Gait/*physiology; Hindlimb/physiology; Horses/*physiology; Locomotion/*physiology; Models, Biological; Video Recording
Abstract OBJECTIVE: To quantify variation in the jumping technique within and among young horses with little jumping experience, establish relationships between kinetic and kinematic variables, and identify a limited set of variables characteristic for detecting differences in jumping performance among horses. ANIMALS: Fifteen 4-year-old Dutch Warmblood horses. PROCEDURE: The horses were raised under standardized conditions and trained in accordance with a fixed protocol for a short period. Subsequently, horses were analyzed kinematically during free jumping over a fence with a height of 1.05 m. RESULTS: Within-horse variation in all variables that quantified jumping technique was smaller than variation among horses. However, some horses had less variation than others. Height of the center of gravity (CG) at the apex of the jump ranged from 1.80 to 2.01 m among horses; this variation could be explained by the variation in vertical velocity of the CG at takeoff (r, 0.78). Horses that had higher vertical velocity at takeoff left the ground and landed again farther from the fence, had shorter push-off phases for the forelimbs and hind limbs, and generated greater vertical acceleration of the CG primarily during the hind limb push-off. However, all horses cleared the fence successfully, independent of jumping technique. CONCLUSIONS AND CLINICAL RELEVANCE: Each horse had its own jumping technique. Differences among techniques were characterized by variations in the vertical velocity of the CG at takeoff. It must be determined whether jumping performance later in life can be predicted from observing free jumps of young horses.
Address Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 12, NL-3584 CM Utrecht, The Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-9645 ISBN Medium
Area Expedition Conference
Notes PMID:15281652 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 3772
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Author Galloux, P.; Barrey, E.
Title Components of the total kinetic moment in jumping horses Type Journal Article
Year 1997 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 23 Pages 41-44
Keywords Algorithms; Animals; Exertion/*physiology; Female; Gravitation; Horses/*physiology; Kinetics; Locomotion/*physiology; Male; Models, Biological; Movement/*physiology; Video Recording
Abstract Thirty horses were filmed with a panning camera operating at 50 frames/s as they jumped over a 1.20 x 1.20 m fence. The markers of 9 joints on the horse and 7 joints on the rider were tracked in 2D with the TrackEye system. The centre of gravity and moment of inertia of each segment were calculated using a geometric algorithm and a cylindric model, respectively. The kinetic moment of each part of the horse was calculated after filtering, and resampling of data. This method showed the relative contribution of each body segment to the body overall rotation during the take-off, jump and landing phases. It was found that the trunk, hindlimbs and head-neck had the greatest influence. The coordination between the motion of the body segments allowed the horse to control its angular speed of rotation over the fence. This remained nearly constant during the airborne phase (120 +/- 5 degrees/s). During the airborne phase, the kinetic moment was constant because its value was equal to the moment of the external forces (722 +/- 125 kg x m2/s).
Address Ecole Nationale d'Equitation, Terrefort, Saumur, France
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Language English Summary Language Original Title
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Notes PMID:9354287 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 3797
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Author Gonzalez-Fernandez, J.M.; Atta, S.E.
Title Facilitated transport of oxygen in the presence of membranes in the diffusion path Type Journal Article
Year 1982 Publication Biophysical Journal Abbreviated Journal Biophys J
Volume 38 Issue 2 Pages 133-141
Keywords Animals; Biological Transport, Active; Cell Membrane/*metabolism; Diffusion; Dogs; Horses; Humans; Kinetics; Mathematics; *Models, Biological; Muscles/*metabolism; Oxygen/*metabolism
Abstract Most of the experimental observations on facilitated transport have been done with millipore filters, and all the theoretical studies have assumed homogeneous spatial properties. In striated muscle there exist membranes that may impede the diffusion of the carrier myoglobin. In this paper a theoretical study is undertaken to analyze the transport in the presence of membranes in the diffusion path. For the numerical computations physiologically relevant values of the parameters were chosen. The numerical results indicate that the presence of membranes tends to decrease the facilitation. For the nonlinear chemical kinetics of the reaction of oxygen with the carrier, this decrement also depends on the location of the membranes. At the higher oxygen concentration side of each membrane the flow of combined oxygen is transferred to the flow of dissolved oxygen. The reverse process occurs at the lower concentration side. Jump discontinuities of the concentration of the oxygen-carrier compound at each membrane are associated with these transfers. The decrement of facilitation is due to the cumulative effect of these jump discontinuities.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-3495 ISBN Medium
Area Expedition Conference
Notes PMID:7093418 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 3806
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Author Kingston, J.K.; Soppet, G.M.; Rogers, C.W.; Firth, E.C.
Title Use of a global positioning and heart rate monitoring system to assess training load in a group of thoroughbred racehorses Type Journal Article
Year 2006 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 36 Pages 106-109
Keywords Analysis of Variance; Animals; Female; *Geographic Information Systems; Heart Rate/*physiology; Horses/*physiology; Male; Monitoring, Physiologic/veterinary; Physical Conditioning, Animal/*physiology; Satellite Communications; Telemetry/methods/*veterinary
Abstract REASONS FOR PERFORMING STUDY: Training is an important variable for determining athletic success. Nonetheless, there has been minimal scientific evaluation of racehorse training programmes. Training of racehorses focuses on running the horses at certain speeds using a combination of a stopwatch and rider's 'feel' for a horse's work intensity. Consequently, actual work intensity for individual horses is not clearly defined. OBJECTIVES: To 1) utilise a combined global positioning system (GPS) and heart rate monitor system to quantify training intensity and physiological responses of a group of racehorses undergoing training and racing; and 2) compare the workload measured by the GPS to that timed and recorded daily by a racehorse trainer. METHODS: Nineteen racehorses age 3 years were followed through a traditional training and racing programme over a 4 month period. Daily GPS and heart rate data together with the trainer's timing and distance data were collected while the horses were trained. Data were analysed using an ANOVA for repeated measures. RESULTS: The combined GPS/heart rate monitoring system detected different heart rate responses in individual horses subjected to the same training workouts. The average speeds detected with the GPS system were in agreement with average speeds timed by the trainer. However, peak speeds reached during training were significantly greater (P<0.05) than those estimated with stopwatch timing. The horses average training speeds increased significantly over the duration of the training period. CONCLUSIONS AND POTENTIAL RELEVANCE: The results from this study show that a GPS/heart rate monitor system provides a reliable measure of daily workload in horses during training. This technology provides a detailed picture of horses' training sessions and has the potential to provide a greater insight into the types of training that may predispose horses to injury.
Address Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes PMID:17402402 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 4014
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Author Santamaria, S.; Bobbert, M.F.; Back, W.; Barneveld, A.; van Weeren, P.R.
Title Effect of early training on the jumping technique of horses Type Journal Article
Year 2005 Publication American Journal of Veterinary Research Abbreviated Journal Am J Vet Res
Volume 66 Issue 3 Pages 418-424
Keywords Age Factors; Analysis of Variance; Animals; Biomechanics; Forelimb/physiology; Gait/*physiology; Hindlimb/physiology; Horses/growth & development/*physiology; Locomotion/*physiology; Models, Biological; Physical Conditioning, Animal/*methods
Abstract OBJECTIVE: To investigate the effects of early training for jumping by comparing the jumping technique of horses that had received early training with that of horses raised conventionally. ANIMALS: 40 Dutch Warmblood horses. PROCEDURE: The horses were analyzed kinematically during free jumping at 6 months of age. Subsequently, they were allocated into a control group that was raised conventionally and an experimental group that received 30 months of early training starting at 6 months of age. At 4 years of age, after a period of rest in pasture and a short period of training with a rider, both groups were analyzed kinematically during free jumping. Subsequently, both groups started a 1-year intensive training for jumping, and at 5 years of age, they were again analyzed kinematically during free jumping. In addition, the horses competed in a puissance competition to test maximal performance. RESULTS: Whereas there were no differences in jumping technique between experimental and control horses at 6 months of age, at 4 years, the experimental horses jumped in a more effective manner than the control horses; they raised their center of gravity less yet cleared more fences successfully than the control horses. However, at 5 years of age, these differences were not detected. Furthermore, the experimental horses did not perform better than the control horses in the puissance competition. CONCLUSIONS AND CLINICAL RELEVANCE: Specific training for jumping of horses at an early age is unnecessary because the effects on jumping technique and jumping capacity are not permanent.
Address Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, NL-3584 CM Utrecht, The Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-9645 ISBN Medium
Area Expedition Conference
Notes PMID:15822585 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 4037
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Author Ikeda, M.; Patterson, K.; Graham, K.S.; Ralph, M.A.L.; Hodges, J.R.
Title A horse of a different colour: do patients with semantic dementia recognise different versions of the same object as the same? Type Journal Article
Year 2006 Publication Neuropsychologia Abbreviated Journal Neuropsychologia
Volume 44 Issue 4 Pages 566-575
Keywords Adult; Aged; Anomia/diagnosis/psychology; Atrophy; *Attention; Color Perception; Dementia/*diagnosis/psychology; *Discrimination Learning; Dominance, Cerebral; Female; Humans; Male; *Memory, Short-Term; Middle Aged; Neuropsychological Tests; Orientation; *Pattern Recognition, Visual; Reference Values; Retention (Psychology); Semantics; Size Perception; Temporal Lobe/pathology
Abstract Ten patients with semantic dementia resulting from bilateral anterior temporal lobe atrophy, and 10 matched controls, were tested on an object recognition task in which they were invited to choose (from a four-item array) the picture representing “the same thing” as an object picture that they had just inspected and attempted to name. The target in the response array was never physically identical to the studied picture but differed from it – in the various conditions – in size, angle of view, colour or exemplar (e.g. a different breed of dog). In one test block for each patient, the response array was presented immediately after the studied picture was removed; in another block, a 2 min filled delay was inserted between study and test. The patients performed relatively well when the studied object and target response differed only in the size of the picture on the page, but were significantly impaired as a group in the other three type-of-change conditions, even with no delay between study and test. The five patients whose structural brain imaging revealed major right-temporal atrophy were more impaired overall, and also more affected by the 2 min delay, than the five patients with an asymmetric pattern characterised by predominant left-sided atrophy. These results are interpreted in terms of a hypothesis that successful classification of an object token as an object type is not a pre-semantic ability but rather results from interaction of perceptual and conceptual processing.
Address Department of Neuropsychiatry, Ehime University School of Medicine, Shitsukawa, Toon City, Ehime 791-0295, Japan. mikeda@m.ehime-u.ac.jp
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-3932 ISBN Medium
Area Expedition Conference
Notes PMID:16115656 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 4059
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Author Carroll, J.; Murphy, C.J.; Neitz, M.; Hoeve, J.N.; Neitz, J.
Title Photopigment basis for dichromatic color vision in the horse Type Journal Article
Year 2001 Publication Journal of Vision Abbreviated Journal J Vis
Volume 1 Issue 2 Pages 80-87
Keywords Adaptation, Physiological; Animals; Color Perception/*physiology; Cones (Retina)/chemistry/*physiology; Electroretinography; Horses/*physiology; Photic Stimulation; Phototransduction/physiology; Retinal Pigments/analysis/*physiology; Visual Perception/physiology
Abstract Horses, like other ungulates, are active in the day, at dusk, dawn, and night; and, they have eyes designed to have both high sensitivity for vision in dim light and good visual acuity under higher light levels (Walls, 1942). Typically, daytime activity is associated with the presence of multiple cone classes and color-vision capacity (Jacobs, 1993). Previous studies in other ungulates, such as pigs, goats, cows, sheep and deer, have shown that they have two spectrally different cone types, and hence, at least the photopigment basis for dichromatic color vision (Neitz & Jacobs, 1989; Jacobs, Deegan II, Neitz, Murphy, Miller, & Marchinton, 1994; Jacobs, Deegan II, & Neitz, 1998). Here, electroretinogram flicker photometry was used to measure the spectral sensitivities of the cones in the domestic horse (Equus caballus). Two distinct spectral mechanisms were identified and are consistent with the presence of a short-wavelength-sensitive (S) and a middle-to-long-wavelength-sensitive (M/L) cone. The spectral sensitivity of the S cone was estimated to have a peak of 428 nm, while the M/L cone had a peak of 539 nm. These two cone types would provide the basis for dichromatic color vision consistent with recent results from behavioral testing of horses (Macuda & Timney, 1999; Macuda & Timney, 2000; Timney & Macuda, 2001). The spectral peak of the M/L cone photopigment measured here, in vivo, is similar to that obtained when the gene was sequenced, cloned, and expressed in vitro (Yokoyama & Radlwimmer, 1999). Of the ungulates that have been studied to date, all have the photopigment basis for dichromatic color vision; however, they differ considerably from one another in the spectral tuning of their cone pigments. These differences may represent adaptations to the different visual requirements of different species.
Address Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1534-7362 ISBN Medium
Area Expedition Conference
Notes PMID:12678603 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 4060
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Author Touma, C.; Palme, R.; Sachser, N.
Title Analyzing corticosterone metabolites in fecal samples of mice: a noninvasive technique to monitor stress hormones Type Journal Article
Year 2004 Publication Hormones and Behavior Abbreviated Journal Horm Behav
Volume 45 Issue 1 Pages 10-22
Keywords Adrenal Cortex/drug effects; Adrenal Cortex Function Tests; Adrenocorticotropic Hormone/pharmacology; Analysis of Variance; Animals; Circadian Rhythm; Corticosterone/*analysis/metabolism; Dexamethasone/pharmacology; Feces/*chemistry; Female; Immunoenzyme Techniques/*methods; Male; Mice; Mice, Inbred C57BL; Models, Animal; Reproducibility of Results; Stress, Psychological/*metabolism
Abstract In small animals like mice, the monitoring of endocrine functions over time is constrained seriously by the adverse effects of blood sampling. Therefore, noninvasive techniques to monitor, for example, stress hormones in these animals are highly demanded in laboratory as well as in field research. The aim of our study was to evaluate the biological relevance of a recently developed technique to monitor stress hormone metabolites in fecal samples of laboratory mice. In total, six experiments were performed using six male and six female mice each. Two adrenocorticotropic hormone (ACTH) challenge tests, two dexamethasone (Dex) suppression tests and two control experiments [investigating effects of the injection procedure itself and the diurnal variation (DV) of glucocorticoids (GCs), respectively] were conducted. The experiments clearly demonstrated that pharmacological stimulation and suppression of adrenocortical activity was reflected accurately by means of corticosterone metabolite (CM) measurements in the feces of males and females. Furthermore, the technique proved sensitive enough to detect dosage-dependent effects of the ACTH/Dex treatment and facilitated to reveal profound effects of the injection procedure itself. Even the naturally occurring DV of GCs could be monitored reliably. Thus, our results confirm that measurement of fecal CM with the recently established 5alpha-pregnane-3beta,11beta,21-triol-20-one enzyme immunoassay is a very powerful tool to monitor adrenocortical activity in laboratory mice. Since mice represent the vast majority of all rodents used for research worldwide and the number of transgenic and knockout mice utilized as animal models is still increasing, this noninvasive technique can open new perspectives in biomedical and behavioral science.
Address Department of Behavioural Biology, University of Muenster, D-48149 Muenster, Germany. touma@uni-muenster.de
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-506X ISBN Medium
Area Expedition Conference
Notes PMID:14733887 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 4084
Permanent link to this record