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De Stoppelaire, G. H., Gillespie, T. W., Brock, J. C., & Tobin, G. A. (2004). Use of remote sensing techniques to determine the effects of grazing on vegetation cover and dune elevation at Assateague Island National Seashore: impact of horses. Environ Manage, 34(5), 642–649.
Abstract: The effects of grazing by feral horses on vegetation and dune topography at Assateague Island National Seashore were investigated using color-infrared imagery, lidar surveys, and field measurements. Five pairs of fenced and unfenced plots (300 m2) established in 1993 on sand flats and small dunes with similar elevation, topography, and vegetation cover were used for this study. Color-infrared imagery from 1998 and field measurements from 2001 indicated that there was a significant difference in vegetation cover between the fenced and unfenced plot-pairs over the study period. Fenced plots contained a higher percentage of vegetation cover that was dominated by American beachgrass (Ammophila breviligulata). Lidar surveys from 1997, 1999, and 2000 showed that there were significant differences in elevation and topography between fenced and unfenced plot-pairs. Fenced plots were, on average, 0.63 m higher than unfenced plots, whereas unfenced plots had generally decreased in elevation after establishment in 1993. Results demonstrate that feral horse grazing has had a significant impact on dune formation and has contributed to the erosion of dunes at Assateague Island. The findings suggest that unless the size of the feral horse population is reduced, grazing will continue to foster unnaturally high rates of dune erosion into the future. In order to maintain the natural processes that historically occurred on barrier islands, much larger fenced exclosures would be required to prevent horse grazing.
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Kingston, J. K., Soppet, G. M., Rogers, C. W., & Firth, E. C. (2006). Use of a global positioning and heart rate monitoring system to assess training load in a group of thoroughbred racehorses. Equine Vet J Suppl, (36), 106–109.
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.
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Thompson, J. A., Brown, S. E. 2nd, Riddle, W. T., Seahorn, J. C., & Cohen, N. D. (2005). Use of a Bayesian risk-mapping technique to estimate spatial risks for mare reproductive loss syndrome in Kentucky. Am J Vet Res, 66(1), 17–20.
Abstract: OBJECTIVE: To estimate spatial risks associated with mare reproductive loss syndrome (MRLS) during 2001 among horses in a specific study population and partition the herd effects into those attributable to herd location and those that were spatially random and likely attributable to herd management. Animals-Pregnant broodmares from 62 farms in 7 counties in central Kentucky. PROCEDURE: Veterinarians provided the 2001 abortion incidence proportions for each farm included in the study. Farms were georeferenced and data were analyzed by use of a fully Bayesian risk-mapping technique. RESULTS: Large farm-to-farm variation in MRLS incidence proportions was identified. The farm-to-farm variation was largely attributed to spatial location rather than to spatially random herd effects. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that there are considerable data to support an ecologic cause and potential ecologic risk factors for MRLS. Veterinary practitioners with more detailed knowledge of the ecology in the 7 counties in Kentucky that were investigated may provide additional data that would assist in the deduction of the causal factor of MRLS via informal geographic information systems analyses and suggest factors for inclusion in further investigations.
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Hockenhull, J., & Creighton, E. (2010). Unwanted oral investigative behaviour in horses: A note on the relationship between mugging behaviour, hand-feeding titbits and clicker training. Appl. Anim. Behav. Sci., 127(3-4), 104–107.
Abstract: Unwanted oral investigative in horses has been anecdotally attributed to the practice of hand-feeding. Fears over such behaviour developing as a consequence of using food rewards, for example in clicker training, have been implicated as a common reason for not employing food-based positive reinforcement training techniques. This study used data generated as part of a larger research project, and explored associations between five common oral investigative behaviours and the practices of hand-feeding and clicker training. Data were from a convenience sample of UK leisure horse owners using two self-administered Internet surveys. Ninety-one percent of respondents reported giving their horse food by hand and this practice was significantly associated with three of the five oral investigative behaviours, licking hands (P = 0.006), gently searching clothing (P < 0.001) and roughly searching clothing (P = 0.003). Nipping hands and biting clothes were not associated with hand-feeding, suggesting that risk factors for these behaviours originate outside of this practice. Clicker training techniques were employed by 14% of respondents and their use was not associated with the incidence of any of the five oral investigative behaviours. These findings suggest that horse owners should not be deterred from using food-based positive reinforcement techniques with their horses, as fears that this practice will result in unwanted oral investigative behaviours from their horses appear unfounded.
Keywords: Equine; Horse; Titbits; Food rewards; Clicker training; Mugging behaviour
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Beveridge, W. I. (1993). Unravelling the ecology of influenza A virus. Hist Philos Life Sci, 15(1), 23–32.
Abstract: For 20 years after the influenza A virus was discovered in the early 1930s, it was believed to be almost exclusively a human virus. But in the 1950s closely related viruses were discovered in diseases of horses, pigs and birds. Subsequently influenza A viruses were found to occur frequently in many species of birds, particularly ducks, usually without causing disease. Researchers showed that human and animal strains can hybridise thus producing new strains. Such hybrids may be the cause of pandemics in man. Most pandemics have started in China or eastern Russia where many people are in intimate association with animals. This situation provides a breeding ground for new strains of influenza A virus.
Keywords: Animals; Bird Diseases/epidemiology/*history/microbiology; Birds; Ecology; History, 20th Century; Horse Diseases/epidemiology/*history/microbiology; Horses; Humans; Influenza A virus/*isolation & purification; Influenza, Human/epidemiology/*history/microbiology/*veterinary; Swine; Swine Diseases/epidemiology/*history/microbiology; Zoonoses/history
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van Heel, M. C. V., Kroekenstoel, A. M., van Dierendonck, M. C., van Weeren, P. R., & Back, W. (2006). Uneven feet in a foal may develop as a consequence of lateral grazing behaviour induced by conformational traits. Equine. Vet. J., 38(7), 646–651.
Abstract: REASONS FOR PERFORMING STUDY: Conformational traits are important in breeding, since they may be indicative for performance ability and susceptibility to injuries. OBJECTIVES: To study whether certain desired conformational traits of foals are related to lateralised behaviour while foraging and to the development of uneven feet. METHODS: Twenty-four Warmblood foals, born and raised at the same location, were studied for a year. Foraging behaviour was observed by means of weekly 10 min scan-sampling for 8 h. A preference test (PT) was developed to serve as a standardised tool to determine laterality. The foals were evaluated at age 3, 15, 27 and 55 weeks. The PT and distal limb conformation were used to study the relation between overall body conformation, laterality and the development of uneven feet. Pressure measurements were used to determine the loading patterns under the feet. RESULTS: About 50% of the foals developed a significant preference to protract the same limb systematically while grazing, which resulted in uneven feet and subsequently uneven loading patterns. Foals with relatively long limbs and small heads were predisposed to develop laterality and, consequently unevenness. CONCLUSIONS: Conformational traits may stimulate the development of laterality and therefore indirectly cause uneven feet.
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Saslow, C. A. (2002). Understanding the perceptual world of horses. Appl. Anim. Behav. Sci., 78(2-4), 209–224.
Abstract: From the viewpoint of experimental psychology, there are two problems with our current knowledge of equine perception. The first is that the behavioral and neurophysiological research in this area has enormous gaps, reflecting that this animal is not a convenient laboratory subject. The second is that the horse, having been a close companion to humans for many millennia, entrenched anecdotal wisdom is often hard to separate from scientific fact. Therefore, any summary at present of equine perception has to be provisional. The horse appears to have developed a visual system particularly sensitive to dim light and movement, it may or may not have a weak form of color vision in part of the retina, it has little binocular overlap, and its best acuity is limited to a restricted horizontal band which is aimed primarily by head/neck movements. However, the total field of view is very large. Overall, as would be expected for a prey animal, horse vision appears to have evolved more for detection of predator approach from any angle than for accurate visual identification of stationary objects, especially those seen at a distance. It is likely that, as for most mammals except the primates, horses rely more heavily on their other senses for forming a view of their world. Equine high-frequency hearing extends far above that of humans, but horses may be less able to localize the point of origin of brief sounds. The horse's capacity for chemoreception and its reliance on chemical information for identification may more closely resemble that of the dog than of the human. Its tactile sensitivity is high, and the ability of its brain and body to regulate pain perception appears to be similar to that found in other mammals. There is room for a great deal of future research in both the area of equine perception and sensory-based cognition, but for the present time persons interacting with this animal should be made aware of the importance of the sounds they make, the movements of their bodies, the way they touch the animal, and the odors they emit or carry on their clothing.
Keywords: Horse; Perception; Vision; Olfaction; Touch; Hearing; Pain; Training; Psychophysics; Umwelt
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Kienapfel, K. (2011). Und was meinen die Pferde dazu? – Über das Ausdrucksverhalten von Pferden bei verschiedenen Halsstellungen [ And what are the opinions of the horses? – On the expressive behaviour of horses in different neck positions]. Pferdeheilkunde, 27(4), 357–372-380.
Abstract: The purpose of this study is to find convincing arguments, how horses should be ridden correctly, especially concerning the best head and neck position. Currently in the riding world, the opinions differ: The traditional way is to ride a horse with its nose in front of the vertical, while a new method claims that pulling the nose behind the vertical with an extreme flexion of the poll implies “gymnastic movements”. This article is focussed on the welfare and comfort of the horse in different head-neck positions, expressed by behaviours which document discomfort. As a first step, the behaviour of standing horses was observed while their heads and necks were put into seven postulated or frequently assumed positions. In the hyperflexed position the horses displayed most discomfort (with 49,7% of all reactions, like open mouths, head tossing, tail movements and other signs of resentment). The second strongest reactions of discomfort were shown in the highly raised position of the head (34,9%). The moderately rounded neck position as in traditional dressage lessons was not without signs of discomfort either, but less than the other two positions (11,2%). The high position and the extended position did not cause discomfort at all (0,17% and 0,23% respectively). In a second step, horses moving in all gaits under a rider were observed at competitions without the riders´ knowledge. The total number of observations was divided into two categories (each containing 30 horses) on the basis of the common rules of the FN: ridden with the horse’s nose in front of the vertical and ridden with the horse’s nose behind the vertical. The proportion of horses showing discomfort with the nose behind the vertical was clearly much higher (89,3%) compared to those ridden with the nose in front of the vertical (10,7%). Thus, the horses in the first category displayed signs of discomfort 8 times more frequent than those in the second group. In addition, scans carried out at tournaments showed that 92.8% of the horses were ridden with the nose behind the vertical. A clear result of this study is that the reality of riding differs widely from the rules. These results also show that riding in the hyperflexed position causes a great deal of discomfort for the horses and therefore should be abolished.
Die aktuellen Diskussionen in der Reiterwelt, welche Art und Weise des Reitens, besonders welche Kopf-Hals-Stellung zu erstreben ist, werfen die Frage auf, ob und wie die Pferde selbst ihr Befinden zum Ausdruck bringen. Über die Empfindungen der Pferde in verschiedenen Kopfhaltungen ist bisher sehr wenig bekannt. Deswegen wurde zunächst an stehenden Pferden das Ausdrucksverhalten beobachtet. Missfallensäußerungen häuften sich (mit 49,7% aller gezeigten Verhaltensauffälligkeiten wie Sperren, Rückwärtsgehen und Kopfschlagen) in der aufgerollten, hyperflektierten Stellung des Halses. An zweiter Stelle folgten Unmutsäußerungen in der absolut aufgerichteten Haltung (34,9%). Auch die beigezäumte Haltung wurde nicht ohne Unmutsbekundungen hingenommen, hier war deren Anzahl aber wesentlich geringer (11,2%). Die hohe Kopfstellung (0,17%) und die Dehnungshaltung (0,23%) bereiteten den Tieren kaum Unbehagen. Auch das Ausdrucksverhalten der Pferde unter dem Reiter wurde untersucht. Hierfür wurden, unter Berücksichtigung der schriftlich fixierten Regeln für das Turnierwesen der FN, je 30 Pferde in zwei Kategorien beobachtet: mit der Stirnlinie vor der Senkrechten und Pferde mit der Stirnlinie hinter der Senkrechten. Die Beobachtungen wurden unbemerkt von den Reitern auf den Abreiteplätzen von Turnieren durchgeführt. Die Anzahl an Verhaltensauffälligkeiten der Pferde mit der Stirnlinie hinter der Senkrechten war deutlich (89,3 %) erhöht im Gegensatz zu der anderen Gruppe (10,7 %). Die Pferde mit der Stirnlinie hinter der Senkrechten zeigten 8 Mal mehr Unmutsäußerungen als die mit der Stirnlinie vor der Senkrechten. Entgegen den Regeln der FN zeigten die durchgeführten Scans, dass unmittelbar vor den Prüfungen auf Turnieren 92,8% der Pferde mit der Stirnnasen-Linie hinter der Senkrechten geritten wurden. Ein Befund dieser Studie ist die Feststellung, dass die Praxis deutlich von den Regeln abweicht. Das Reiten mit der Stirnlinie hinter der Senkrechten ist nach diesen Befunden abzulehnen, da die Pferde deutliches Unwohlsein in dieser Haltung signalisieren. |
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Hagen, S. J., & Eaton, W. A. (2000). Two-state expansion and collapse of a polypeptide. J Mol Biol, 301(4), 1019–1027.
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.
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Judge, N. G. (1969). Transport of horses. Aust Vet J, 45(10), 465–469.
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