| Records |
| Author |
Heird, J.C.; Lennon, A.M.; Bell, R.W. |
| Title |
Effects of early experience on the learning ability of yearling horses |
Type |
Journal Article |
| Year |
1981 |
Publication |
Journal of Animal Science |
Abbreviated Journal |
J. Anim Sci. |
| Volume |
53 |
Issue |
5 |
Pages |
1204-1209 |
| Keywords |
Animals; Conditioning (Psychology); Female; *Handling (Psychology); Horses/*physiology; *Learning |
| Abstract |
Twenty-four yearling Quarter Horse fillies were divided into three groups (I) very limited handling, (II) intermediate handling and (III) extensive handling. At about 14 months of age, each horse was preconditioned for 2 weeks and then run in a simple place-learning T-maze test in which it had to locate its feed. Thirty trials were run daily for 20 days, with the location of the feed changed each day. To retire from the maze, a horse had to meet the criterion: 11 correct responses in 12 tries, with the last eight being consecutive. Horses in Group II required the fewest trials to reach criterion. These horses also learned more and had the highest percentage of correct responses (P less than .05). Mean trainability tended to predict learning ability; however, trainability and trials to criterion were not significantly correlated. Mean emotionality scores indicated a tendency for horses in the intermediately handled group to be less emotional than those in Group I or III. Results indicated that horses with an intermediate amount of handling scored higher on an intermediate test of learning. All handled horses scored higher on learning tests than those not handled. |
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Place of Publication |
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| Language |
English |
Summary Language |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0021-8812 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:7319966 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3577 |
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| Author |
Timney, B.; Keil, K. |
| Title |
Local and global stereopsis in the horse |
Type |
Journal Article |
| Year |
1999 |
Publication |
Vision Research |
Abbreviated Journal |
Vision Res |
| Volume |
39 |
Issue |
10 |
Pages |
1861-1867 |
| Keywords |
Animals; Depth Perception/*physiology; Female; Horses/*physiology; Pattern Recognition, Visual/physiology; Psychophysics; Sensory Thresholds/physiology; Vision, Binocular/physiology; Vision, Monocular/physiology |
| Abstract |
Although horses have laterally-placed eyes, there is substantial binocular overlap, allowing for the possibility that these animals have stereopsis. In the first experiment of the present study we measured local stereopsis by obtaining monocular and binocular depth thresholds for renal depth stimuli. On all measures, the horses' binocular performance was superior to their monocular. When depth thresholds were obtained, binocular thresholds were several times superior to those obtained monocularly, suggesting that the animals could use stereoscopic information when it was available. The binocular thresholds averaged about 15 min arc. In the second experiment we obtained evidence for the presence of global stereopsis by testing the animals' ability to discriminate between random-dot stereograms with and without consistent disparity information. When presented with such stimuli they showed a strong preference for the cyclopean equivalent of the positive stimulus with the real depth. These results provide the first behavioral demonstration of a full range of stereoscopic skills in a lateral-eyed mammal. |
| Address |
Department of Psychology, Faculty of Social Science, University of Western Ontario, London, Canada. timney@julian.uwo.ca |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0042-6989 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:10343877 |
Approved |
yes |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3580 |
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| Author |
Pepperberg, I.M.; Brezinsky, M.V. |
| Title |
Acquisition of a relative class concept by an African gray parrot (Psittacus erithacus): discriminations based on relative size |
Type |
Journal Article |
| Year |
1991 |
Publication |
Journal of Comparative Psychology |
Abbreviated Journal |
J Comp Psychol |
| Volume |
105 |
Issue |
3 |
Pages |
286-294 |
| Keywords |
Animals; Aptitude; *Concept Formation; *Discrimination Learning; Form Perception; Male; Mental Recall; *Parrots; *Size Perception; Vocalization, Animal |
| Abstract |
We report that an African gray parrot (Psittacus erithacus), Alex, responds to stimuli on a relative basis. Previous laboratory studies with artificial stimuli (such as pure tones) suggest that birds make relational responses as a secondary strategy, only after they have acquired information about the absolute values of the stimuli. Alex, however, after learning to respond to a small set of exemplars on the basis of relative size, transferred this behavior to novel situations that did not provide specific information about the absolute values of the stimuli. He responded to vocal questions about which was the larger or smaller exemplar by vocally labeling its color or material, and he responded “none” if the exemplars did not differ in size. His overall accuracy was 78.7%. |
| Address |
Northwestern University |
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Place of Publication |
Washington, D.C. : 1983 |
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English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0735-7036 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:1935007 |
Approved |
yes |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3610 |
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| Author |
Sivak, J.G.; Allen, D.B. |
| Title |
An evaluation of the “ramp” retina of the horse eye |
Type |
Journal Article |
| Year |
1975 |
Publication |
Vision Research |
Abbreviated Journal |
Vision Res |
| Volume |
15 |
Issue |
12 |
Pages |
1353-1356 |
| Keywords |
Accommodation, Ocular; Animals; Aqueous Humor/physiology; Cornea/physiology; Freezing; Horses/*anatomy & histology; Lens, Crystalline/anatomy & histology/physiology; Refraction, Ocular; Retina/*anatomy & histology; Vitreous Body/physiology |
| Abstract |
Using a rapid freezing and sectioning technique, the distance between the lens and retina of the horse eye was measured. There is no indication of a ramp retina that could serve accommodation. The pupil axis of the eye coincides with the maximum lens to retina distance. The changes in the lens-retina distance are greater below the axis than above it. Calculations were made of refractive power of the horse eye from measurements of curvature and refractive indices of the ocular tissues. These calculations agree both qualitatively and quantitatively with retinoscopic measurements on live horses. Both show that the refractive state shifts in the direction of hyperopia above and below the axis and that this shift is greater below the axis than above it. Some dynamic accommodative ability in the living eye was observed. |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0042-6989 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:1210017 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3647 |
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| Author |
Rhodin, M.; Johnston, C.; Holm, K.R.; Wennerstrand, J.; Drevemo, S. |
| Title |
The influence of head and neck position on kinematics of the back in riding horses at the walk and trot |
Type |
Journal Article |
| Year |
2005 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
| Volume |
37 |
Issue |
1 |
Pages |
7-11 |
| Keywords |
Acceleration; Animals; Back/*physiology; Biomechanics; Exercise Test/veterinary; Female; Gait/*physiology; Head/*physiology; Horses/*physiology; Male; Movement/physiology; Neck/*physiology; Walking/physiology |
| Abstract |
REASONS FOR PERFORMING STUDY: A common opinion among riders and in the literature is that the positioning of the head and neck influences the back of the horse, but this has not yet been measured objectively. OBJECTIVES: To evaluate the effect of head and neck position on the kinematics of the back in riding horses. METHODS: Eight Warmblood riding horses in regular work were studied on a treadmill at walk and trot with the head and neck in 3 different predetermined positions achieved by side reins attached to the bit and to an anticast roller. The 3-dimensional movement of the thoracolumbar spine was measured from the position of skin-fixed markers recorded by infrared videocameras. RESULTS: Head and neck position influenced the movements of the back, especially at the walk. When the head was fixed in a high position at the walk, the flexion-extension movement and lateral bending of the lumbar back, as well as the axial rotation, were significantly reduced when compared to movements with the head free or in a low position. At walk, head and neck position also significantly influenced stride length, which was shortest with the head in a high position. At trot, the stride length was independent of head position. CONCLUSIONS: Restricting and restraining the position and movement of the head and neck alters the movement of the back and stride characteristics. With the head and neck in a high position stride length and flexion and extension of the caudal back were significantly reduced. POTENTIAL RELEVANCE: Use of side reins in training and rehabilitation programmes should be used with an understanding of the possible effects on the horse's back. |
| Address |
Department of Anatomy, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden |
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Place of Publication |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0425-1644 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:15651727 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3657 |
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| Author |
Anderson, T.M.; McIlwraith, C.W.; Douay, P. |
| Title |
The role of conformation in musculoskeletal problems in the racing Thoroughbred |
Type |
Journal Article |
| Year |
2004 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
| Volume |
36 |
Issue |
7 |
Pages |
571-575 |
| Keywords |
Animals; Carpus, Animal/anatomy & histology/physiology; Horse Diseases/etiology/*pathology/surgery; Horses/*anatomy & histology/injuries/physiology; Likelihood Functions; Logistic Models; Muscle, Skeletal/*anatomy & histology/pathology; Musculoskeletal Diseases/pathology/surgery/*veterinary; Tarsus, Animal/anatomy & histology/physiology; Treatment Outcome |
| Abstract |
REASONS FOR PERFORMING STUDY: The relationship of conformation to future potential injury is a standard approach in practise but, at present, is largely based on subjective observations. OBJECTIVE: To measure conformation in 3-year-old Thoroughbreds and objectively test its relationship with the occurrence of musculoskeletal problems. METHODS: Conformation measurements were taken from photographs using specific reference points marked on the horses and processed on the computer. Clinical observations were recorded for each horse on a regular basis. Stepwise (forward) logistic regression analysis was performed to investigate the relationship between the binary response of the clinical outcomes probability and the conformation variables by the method of maximum likelihood. RESULTS: Clinical outcomes significantly (P<0.05) associated with conformational variables included effusion of the front fetlock, effusion of the right carpus, effusion of the carpus, effusion of the hind fetlock, fracture of the left or right carpus, right front fetlock problem and hind fetlock problem. CONCLUSIONS: Offset knees (offset ratio) contributed to fetlock problems. Long pasterns increased the odds of a fracture in the front limb. An increase in the carpal angle as viewed from the front (carpal valgus) may serve as a protective mechanism, as the odds for a carpal fracture and carpal effusion decreased with an increase in the carpal angle. POTENTIAL RELEVANCE: This study demonstrates relationships between conformation and musculoskeletal disease in the racehorse. The information may be useful in selection and management of the racing Thoroughbred. |
| Address |
Colorado State University, Equine Science and Equine Orthopaedic Research Programs, Fort Collins, Colorado 80523, USA |
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Place of Publication |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0425-1644 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:15581320 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3697 |
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| Author |
Gomez Alvarez, C.B.; Rhodin, M.; Bobber, M.F.; Meyer, H.; Weishaupt, M.A.; Johnston, C.; Van Weeren, P.R. |
| Title |
The effect of head and neck position on the thoracolumbar kinematics in the unridden horse |
Type |
Journal Article |
| Year |
2006 |
Publication |
Equine Veterinary Journal. Supplement |
Abbreviated Journal |
Equine Vet J Suppl |
| Volume |
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Issue |
36 |
Pages |
445-451 |
| Keywords |
Animals; Biomechanics; Head/*physiology; Horses/*physiology; Lumbar Vertebrae/physiology; Male; Neck/*physiology; Physical Conditioning, Animal/physiology; Posture/*physiology; Sports; Thoracic Vertebrae/physiology; Weight-Bearing |
| Abstract |
REASONS 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. |
| Address |
Department of Equine Sciences, Utrecht University, Yalelaan 12, 3584 CM Utrecht, The Netherlands |
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Place of Publication |
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English |
Summary Language |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISBN |
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Expedition |
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Conference |
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| Notes |
PMID:17402464 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3702 |
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| Author |
Weishaupt, M.A.; Wiestner, T.; von Peinen, K.; Waldern, N.; Roepstorff, L.; van Weeren, R.; Meyer, H.; Johnston, C. |
| Title |
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 |
Type |
Journal Article |
| Year |
2006 |
Publication |
Equine Veterinary Journal. Supplement |
Abbreviated Journal |
Equine Vet J Suppl |
| Volume |
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Issue |
36 |
Pages |
387-392 |
| Keywords |
Animals; Biomechanics; Exercise Test/instrumentation/methods/*veterinary; Forelimb/physiology; Gait; Head/physiology; Hindlimb/physiology; Horses/*physiology; Locomotion/*physiology; Male; Neck/physiology; Physical Conditioning, Animal/methods/*physiology; Posture; Statistics, Nonparametric; Walking/*physiology |
| Abstract |
REASONS 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 paired t test 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. |
| Address |
Equine Hospital, University of Zurich, CH-8057 Zurich, Switzerland |
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English |
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Conference |
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| Notes |
PMID:17402453 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3704 |
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| Author |
Balakrishnan, G.; Hu, Y.; Spiro, T.G. |
| Title |
Temperature-jump apparatus with Raman detection based on a solid-state tunable (1.80-2.05 microm) kHz optical parametric oscillator laser |
Type |
Journal Article |
| Year |
2006 |
Publication |
Applied Spectroscopy |
Abbreviated Journal |
Appl Spectrosc |
| Volume |
60 |
Issue |
4 |
Pages |
347-351 |
| Keywords |
Animals; Cytochromes c/analysis; Horses; Lasers; Myoglobin/metabolism; Spectrum Analysis, Raman/*instrumentation/*methods; *Temperature |
| Abstract |
The operating characteristics of a pulsed (10 ns) tunable near-infrared (NIR) laser source are described for temperature-jump (T-jump) applications. A Q-switched Nd:YLF laser (approximately 10 ns pulses) with a 1 kHz repetition rate is used to pump a potassium titanyl arsenate (KTA) crystal-based optical parametric oscillator (OPO), producing approximately 1 mJ NIR pulses that are tunable (1.80-2.05 microm) across the 1.9 microm vibrational overtone band of water. This T-jump source has been coupled to a deep ultraviolet (UV) probe laser for Raman studies of protein dynamics. T-jumps of up to 30 degrees C, as measured via the O-H stretching Raman band of water, are readily achieved. Application to cytochrome c unfolding is demonstrated. |
| Address |
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA |
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English |
Summary Language |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0003-7028 |
ISBN |
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Medium |
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Conference |
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| Notes |
PMID:16613628 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3764 |
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| Author |
Hagen, S.J.; Eaton, W.A. |
| Title |
Two-state expansion and collapse of a polypeptide |
Type |
Journal Article |
| Year |
2000 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
J Mol Biol |
| Volume |
301 |
Issue |
4 |
Pages |
1019-1027 |
| Keywords |
Animals; Computer Simulation; Cytochrome c Group/*chemistry/*metabolism; Horses; Kinetics; Lasers; Models, Chemical; Peptides/*chemistry/*metabolism; Protein Conformation; Protein Denaturation; *Protein Folding; Spectrometry, Fluorescence; Temperature; Thermodynamics |
| Abstract |
The initial phase of folding for many proteins is presumed to be the collapse of the polypeptide chain from expanded to compact, but still denatured, conformations. Theory and simulations suggest that this collapse may be a two-state transition, characterized by barrier-crossing kinetics, while the collapse of homopolymers is continuous and multi-phasic. We have used a laser temperature-jump with fluorescence spectroscopy to measure the complete time-course of the collapse of denatured cytochrome c with nanosecond time resolution. We find the process to be exponential in time and thermally activated, with an apparent activation energy approximately 9 k(B)T (after correction for solvent viscosity). These results indicate that polypeptide collapse is kinetically a two-state transition. Because of the observed free energy barrier, the time scale of polypeptide collapse is dramatically slower than is predicted by Langevin models for homopolymer collapse. |
| Address |
Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Building 5, Bethesda, MD, 20892-0520, USA |
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English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0022-2836 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:10966803 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3790 |
| Permanent link to this record |
