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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 Equine Behaviour @ team @ Serial (down) 4060
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Author Madigan, J.E.; Whittemore, J.
Title The role of the equine practitioner in disasters Type Journal Article
Year 2000 Publication Journal of the American Veterinary Medical Association Abbreviated Journal J Am Vet Med Assoc
Volume 216 Issue 8 Pages 1238-1239
Keywords *Animal Husbandry/education; *Animal Welfare; Animals; Disaster Planning; *Horses; *Natural Disasters; United States; *Veterinary Medicine
Abstract
Address Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis 95616, 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 0003-1488 ISBN Medium
Area Expedition Conference
Notes PMID:10767959 Approved no
Call Number Equine Behaviour @ team @ Serial (down) 4055
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Author Elsaesser, F.; Klobasa, F.; Ellendorff, F.
Title ACTH stimulation test for the determination of salivary cortisol and of cortisol responses as markers of the training status/fitness of warm-blooded sports horses] Type Journal Article
Year 2001 Publication DTW. Deutsche Tierarztliche Wochenschrift Abbreviated Journal Dtsch Tierarztl Wochenschr
Volume 108 Issue 1 Pages 31-36
Keywords Adrenocorticotropic Hormone/*diagnostic use; Animals; Health; Horses/*physiology; Hydrocortisone/*analysis/*secretion; Male; Orchiectomy; *Physical Conditioning, Animal; Running; Saliva/*chemistry; Walking
Abstract Previous work (Marc et al., 2000) suggested that plasma cortisol responses to treadmill exercise or ACTH injection are a reliable marker for performance evaluation in warmblood horses. For practical purposes blood sample collections and treadmill exercise tests are somewhat troublesome and time consuming. The goal of this study was thus to evaluate the use of saliva for cortisol determination (by direct EIA) as a marker for performance and to investigate the reliability and repeatability of plasma cortisol responses to a single i.v. injection of ACTH (50 micrograms or 250 micrograms). Furthermore, the effect of training horses for 8 weeks 3 times per week covering the same distance (increasing from 3.5 km during the first week to 8 km during the last week) either by trotting (approximately 240 m/min) or by cantering (375 m/min) was investigated. For this purpose initially ten four-year-old Hannovarian geldings, all reared in the same State stud, were used. Mean overall correlation between salivary cortisol and plasma cortisol concentrations was 0.64 when samples of various points of time were used. However, in spite of attempts to standardize saliva sample collection, correlation between salivary cortisol levels and plasma cortisol levels at distinct points of time in different tests were low and significant (r = 0.85, p < 0.02) only in one test. Thus, salivary cortisol measurements for diagnostic purposes are not reliable or useful. The repeatability of plasma cortisol responses to ACTH for untrained and trained horses were r = 0.86 and r = 0.8 respectively (p < or = 0.01 and p < or = 0.05 respectively). Training horses either by trotting or cantering did not affect the cortisol response either to treadmill exercise or to stimulation by ACTH. It is concluded that the relationship between salivary cortisol levels and plasma cortisol levels is not close enough to allow the use of salivary cortisol determination as marker of the training status/fitness of horses. The repeatability of the cortisol response to ACTH is similar to the cortisol response to treadmill exercise. Based on plasma cortisol responses to ACTH or treadmill exercise training horses by cantering at low speed is not superior to training by trotting for the fitness of horses.
Address Institut fur Tierzucht und Tierverhalten Mariensee (FAL), Holtystrasse 10, 31535 Neustadt. elsaesser@tzv.fal.de
Corporate Author Thesis
Publisher Place of Publication Editor
Language German Summary Language Original Title ACTH Stimulationstest und Bestimmung von Cortisol im Blut und Speichel zur Bewertung des Trainingszustands/der Kondition beim Warmblutpferd
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0341-6593 ISBN Medium
Area Expedition Conference
Notes PMID:11232423 Approved no
Call Number Equine Behaviour @ team @ Serial (down) 4053
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Author Robert, C.; Valette, J.P.; Denoix, J.M.
Title The effects of treadmill inclination and speed on the activity of three trunk muscles in the trotting horse Type Journal Article
Year 2001 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J
Volume 33 Issue 5 Pages 466-472
Keywords Animals; Biomechanics; Electromyography/methods/veterinary; Exercise Test/veterinary; Gait/physiology; Horses/*physiology; Muscle, Skeletal/*physiology; Physical Conditioning, Animal; Rectus Abdominis/physiology; Time Factors
Abstract The purpose of this study was to evaluate the effects of speed and slope on the activity of trunk muscles. The electromyographic (EMG) activity of the splenius (Sp), longissimus dorsi (LD) and rectus abdominis (RA) muscles was recorded with surface electrodes during treadmill locomotion at trot for different combinations of speed (3.5 to 6 m/s) and slope (0 to 6%). Raw EMG signals were processed to determine activity duration, onset and end and integrated EMG (IEMG). For the 3 muscles investigated, onset and end of activity were obtained earlier in the stride cycle when speed increased. A longer duration of activity for the LD, a shorter duration for the RA and an unchanged duration for the Sp were also observed. The IEMG of the latter was poorly affected by speed, whereas it increased linearly with speed for the 2 other muscles. When treadmill inclination changed from 0 to 6%, EMG activity of the LD and RA began and ended later; a longer activity duration was noted. Temporal parameters for Sp did not change with slope. A significant and progressive increase in the IEMG of the 3 muscles was observed with increasing slope. This evaluation of the activity of trunk muscles provides objective data for the use of speed or slope in training programmes.
Address UMR INRA-DGER, Biomecanique et Pathalogie Locomotrice du Cheval, UP Anatomie, Ecole Nationale Veterinaire d'Alfort, 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:11558741 Approved no
Call Number Equine Behaviour @ team @ Serial (down) 4052
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Author Hernandez, J.; Hawkins, D.L.
Title Training failure among yearling horses Type Journal Article
Year 2001 Publication American Journal of Veterinary Research Abbreviated Journal Am J Vet Res
Volume 62 Issue 9 Pages 1418-1422
Keywords Animals; Female; Florida; Horses/*physiology; Lameness, Animal/*economics; Male; Physical Conditioning, Animal/adverse effects/economics; Respiratory Tract Diseases/economics/*veterinary; Statistics, Nonparametric
Abstract OBJECTIVE: To compare financial returns between pinhooked yearling horses (ie, bought and trained for approximately 5 months with the goal of selling the horse at “2-year-olds in training” sales) that had mild or severe training failure and horses that had planned versus nonplanned training failure. ANIMALS: 40 Thoroughbred pinhooked yearling horses. PROCEDURE: During the period from September 1998 through and April 1999, 20 horses had mild training failure (1 to 11 days lost), and 20 horses had severe training failure (13 to 108 days lost). Horses were assigned to these 2 groups on the basis of frequency distribution (median) of days lost during training. Horses were also categorized on the basis of type of training failure (planned vs nonplanned training failure). The outcome of primary interest was financial return. Median financial returns were compared among groups by use of the Mann-Whitney U test. RESULTS: Median financial returns for horses that had severe training failure ($1,000) were significantly different, compared with horses that had mild training failure ($24,000). Analysis of results also indicated that median returns were significantly different among horses that had planned training failure (-$2,000; eg, horses with radiographic abnormalities detected during routine prepurchase examinations that required surgical treatment, resulting in days lost during training), compared with horses that did not ($10,000). CONCLUSIONS AND CLINICAL RELEVANCE: Training failure has an economic impact on revenues in pinhooked yearling horses. Lameness, planned training failure, respiratory disease, and ringworm were common and important causes of training failure.
Address Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610-0136, 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 0002-9645 ISBN Medium
Area Expedition Conference
Notes PMID:11560271 Approved no
Call Number Equine Behaviour @ team @ Serial (down) 4051
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Author Robert, C.; Audigie, F.; Valette, J.P.; Pourcelot, P.; Denoix, J.M.
Title Effects of treadmill speed on the mechanics of the back in the trotting saddlehorse Type Journal Article
Year 2001 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 33 Pages 154-159
Keywords Animals; Biomechanics; Electromyography/veterinary; Exercise Test/veterinary; Horses/*physiology; Locomotion/*physiology; Muscle, Skeletal/*physiology; Range of Motion, Articular/*physiology; Spine/*physiology; Video Recording
Abstract Speed related changes in trunk mechanics have not yet been investigated, although high-speed training is currently used in the horse. To evaluate the effects of speed on back kinematics and trunk muscles activity, 4 saddle horses were recorded while trotting on a horizontal treadmill at speeds ranging from 3.5 to 6 m/s. The 3-dimensional (3-D) trajectories of skin markers on the left side of the horse and the dorsal midline of the trunk were established. Electrical activity was simultaneously obtained from the longissimus dorsi (LD) and rectus abdominis (RA) muscles using surface electrodes. Ten consecutive strides were analysed for each horse at each of the 5 velocity steps. Electromyographic and kinematic data were time-standardised to the duration of the stride cycle and compared using an analysis of variance. The back extended during the first part of each diagonal stance phase when the RA was active and the back flexed during the second part of each diagonal stance phase when the LD was active. The onset and end of muscle activity came earlier in the stride cycle and muscle activity intensity increased when speed increased. The amplitude of vertical movement of the trunk and the maximal angles of flexion decreased with increasing speed, whereas the extension angles remained unchanged. This resulted in a decreased range of back flexion-extension. This study confirms that the primary role of trunk muscles is to control the stiffness of the back rather than to induce movements. Understanding the effects of speed on the back of healthy horses is a prerequisite for the prevention and treatment of back pathology.
Address UMR INRA, Biomecanique et Pathologie Locomotrice du Cheval, UP d'Anatomie, Ecole Nationale Veterinaire d'Alfort, 7 Avenue du General de Gaulle, F-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 ISBN Medium
Area Expedition Conference
Notes PMID:11721558 Approved no
Call Number Equine Behaviour @ team @ Serial (down) 4050
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Author Voss, B.; Mohr, E.; Krzywanek, H.
Title Effects of aqua-treadmill exercise on selected blood parameters and on heart-rate variability of horses Type Journal Article
Year 2002 Publication Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine Abbreviated Journal J Vet Med A Physiol Pathol Clin Med
Volume 49 Issue 3 Pages 137-143
Keywords Animals; Electrocardiography/veterinary; Exercise Test/veterinary; Female; Heart Rate/*physiology; Hemoglobins/metabolism; Horses/*physiology; Lactic Acid/blood; Male; Physical Conditioning, Animal/*physiology; Water
Abstract The objectives of the present study were to investigate the effects of Aquatraining of horses (aqua-treadmill exercise; treadmill manufactured by Equitech – L.u.S. Equipment, Warendorf, Germany) on selected blood parameters [lactic acid concentration (mmol/l), haemoglobin content (g/l)] and on heart-rate variability (HRV) [heart rate (beats per min; b.p.m.), standard deviation of all NN-intervals (SDNN; ms), normalized power of the low and high frequency band (LFnorm, Hfnorm; au), % recurrence, % determinism and ratio(corr)]. Seven horses performed six exercise tests with different work loads (walking (x = 1.56 +/- 0.08 m/s) and trotting (x = 2.9 +/- 0.13 m/s): dry, water above the carpus and water above the elbow). The standardized test-protocol was: 5 min warm-up at walk while the water was pumped in, followed by the 20-min exercise period at walk or trot, followed by a 5-min walk while pumping out the water. Blood samples were taken prior to each test at rest in the stable, as well as exactly 5 min after the end of the 20-min exercise period. Electrocardiograms were recorded during rest and the 20-min exercise period. Compared to rest, neither the chosen velocities, the two water levels, nor the dry tests led to a significant increase of the lactic acid concentration in any horse. The haemoglobin content showed a significant increase as a result of exercise. Significant differences could be found between the heart rates at rest and the six exercise tests and between the mean of the levels 'walking' and the mean of the levels 'trotting'. An exercise-induced change of HRV was characterized by a decreasing SDNN, a significantly higher LFnorm (sympathetic influence) combined with a significantly lower HF(norm) power (parasympathetic activity) and a rising degree of order (significantly higher % determinism and nearly unchanged % recurrence) and stability (significantly rising ratio(corr)) of the recurrence plot. In conclusion, the used training-protocol for aqua-treadmill exercises only represents a medium-sized aerobic work load for horses, but the different levels of burden were indicated especially by changes in HRV.
Address Institute for Veterinary Physiology of the Free University Berlin, Germany
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 0931-184X ISBN Medium
Area Expedition Conference
Notes PMID:12019954 Approved no
Call Number Equine Behaviour @ team @ Serial (down) 4049
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Author Golland, L.C.; Evans, D.L.; McGowan, C.M.; Hodgson, D.R.; Rose, R.J.
Title The effects of overtraining on blood volumes in standardbred racehorses Type Journal Article
Year 2003 Publication Veterinary Journal (London, England : 1997) Abbreviated Journal Vet J
Volume 165 Issue 3 Pages 228-233
Keywords Animals; *Blood Volume; Erythrocytes/*physiology; Hematocrit/veterinary; Horse Diseases/etiology/*physiopathology; Horses; Male; *Physical Conditioning, Animal; Physical Endurance
Abstract Red blood cell hypervolaemia has been used for diagnosis of overtraining in racehorses, and has been suggested as a mechanism of this cause of loss of racing performance. The effects of overload training (OLT) on the plasma, blood and red cell volumes were investigated in a prospective study in 12 Standardbred horses. Measurements of blood volumes were made after eight and 32 weeks of an exercise training study. Horses were randomly allocated to OLT and control groups (n=6) after 16 weeks of training. Training duration and intensity were increased more rapidly for the OLT group from week 16, until overtraining was diagnosed in week 32.There were no significant effects of OLT on plasma, blood or total red cell volumes between weeks eight and 32. These volumes significantly decreased with time. Maximal haematocrit after exercise was lower (P<0.05) in the OT group in week 32 (0.57+/-0.003% L/L) than in week eight (0.59+/-0.004 L/L). It was concluded that red cell hypervolaemia was not a mechanism for the decrease in capacity for exercise that occurs with overtraining.
Address Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
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 1090-0233 ISBN Medium
Area Expedition Conference
Notes PMID:12672368 Approved no
Call Number Equine Behaviour @ team @ Serial (down) 4045
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Author Cassiat, G.; Pourcelot, P.; Tavernier, L.; Geiger, D.; Denoix, J.M.; Degueurce, D.
Title Influence of individual competition level on back kinematics of horses jumping a vertical fence Type Journal Article
Year 2004 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J
Volume 36 Issue 8 Pages 748-753
Keywords Animals; Back/*physiology; Biomechanics; Female; Forelimb/*physiology; Gait/*physiology; Hindlimb/*physiology; Horses/*physiology; Image Processing, Computer-Assisted; Imaging, Three-Dimensional/veterinary; Locomotion/physiology; Male; Video Recording
Abstract REASONS FOR PERFORMING STUDY: The costs and investments required for the purchase and training of showjumpers justify the need to find selection means for jumping horses. Use of objective kinematic criteria correlated to jumping ability could be helpful for this assessment. OBJECTIVES: To compare back kinematics between 2 groups of horses of different competition levels (Group 1, competing at high level; Group 2 competing at low level) while free jumping over a 1 m vertical fence. METHODS: Three-dimensional recordings were performed using 2 panning cameras. Kinematic parameters of the withers and tuber sacrale (vertical displacement, vertical and horizontal velocities), backline inclination and flexion-extension motion of the 3 main dorsal segments (thoracic, thoracolumbar and lumbosacral) were analysed. RESULTS: Group 2 horses had a lower displacement of their withers and tuber sacrale from the end of the last approach stride until the first departure stride (P<0.05). As a result, they increased the flexion of their thoracolumbar and lumbosacral junctions during the hindlimb swing phase before take-off (P<0.05). However, withers and tuber sacrale velocities were slightly modified. Group 1 horses pitched their backline less forward during the forelimb stance phase before take-off and straightened it more after landing (P<0.05), probably indicating a more efficient strutting action of their forelimbs. CONCLUSIONS AND POTENTIAL RELEVANCE: Because significant differences in back motion were found between good and poor jumpers when jumping a 1 m high fence, criteria based on certain back kinematics can be developed that may help in the selection of talented showjumpers.
Address UMR INRA-ENVA de Biomecanique et Pathologie Locomotrice du Cheval, Ecole Nationale Veterinaire d'Alfort, 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:15656509 Approved no
Call Number Equine Behaviour @ team @ Serial (down) 4042
Permanent link to this record
 

 
Author Fruehwirth, B.; Peham, C.; Scheidl, M.; Schobesberger, H.
Title Evaluation of pressure distribution under an English saddle at walk, trot and canter Type Journal Article
Year 2004 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J
Volume 36 Issue 8 Pages 754-757
Keywords Animals; Back/*physiology; Biomechanics; Body Weight/physiology; Exercise Test/veterinary; Gait/*physiology; Horses/*physiology; Humans; Locomotion/*physiology; Pressure
Abstract REASONS FOR PERFORMING STUDY: Basic information about the influence of a rider on the equine back is currently lacking. HYPOTHESIS: That pressure distribution under a saddle is different between the walk, trot and canter. METHODS: Twelve horses without clinical signs of back pain were ridden. At least 6 motion cycles at walk, trot and canter were measured kinematically. Using a saddle pad, the pressure distribution was recorded. The maximum overall force (MOF) and centre of pressure (COP) were calculated. The range of back movement was determined from a marker placed on the withers. RESULTS: MOF and COP showed a consistent time pattern in each gait. MOF was 12.1 +/- 1.2 and 243 +/- 4.6 N/kg at walk and trot, respectively, in the ridden horse. In the unridden horse MOF was 172.7 +/- 11.8 N (walk) and 302.4 +/- 33.9 N (trot). At ridden canter, MOF was 27.2 +/- 4.4 N/kg. The range of motion of the back of the ridden horse was significantly lower compared to the unridden, saddled horse. CONCLUSIONS AND POTENTIAL RELEVANCE: Analyses may help quantitative and objective evaluation of the interaction between rider and horse as mediated through the saddle. The information presented is therefore of importance to riders, saddlers and equine clinicians. With the technique used in this study, style, skill and training level of different riders can be quantified, which would give the opportunity to detect potentially harmful influences and create opportunities for improvement.
Address Movement Science Group, Department V, Clinic of Orthopaedics in Ungulates, University of Veterinary Medicine, Vienna, Austria
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:15656510 Approved no
Call Number Equine Behaviour @ team @ Serial (down) 4041
Permanent link to this record