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Gomez Alvarez, C. B., Rhodin, M., Bobber, M. F., Meyer, H., Weishaupt, M. A., Johnston, C., et al. (2006). The effect of head and neck position on the thoracolumbar kinematics in the unridden horse. Equine Vet J Suppl, (36), 445–451.
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.
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Weishaupt, M. A., Wiestner, T., von Peinen, K., Waldern, N., Roepstorff, L., van Weeren, R., et al. (2006). 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. Equine Vet J Suppl, (36), 387–392.
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.
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Cooper, J. J., & Albentosa, M. J. (2005). Behavioural adaptation in the domestic horse: potential role of apparently abnormal responses including stereotypic behaviour. Livest. Prod. Sci., 92(2), 177–182.
Abstract: Classically, biologists have considered adaptation of behavioural characteristics in terms of long-term functional benefits to the individual, such as survival or reproductive fitness. In captive species, including the domestic horse, this level of explanation is limited, as for the most part, horses are housed in conditions that differ markedly from those in which they evolved. In addition, an individual horse's reproductive fitness is largely determined by man rather than its own behavioural strategies. Perhaps for reasons of this kind, explanations of behavioural adaptation to environmental challenges by domestic animals, including the capacity to learn new responses to these challenges, tend to concentrate on the proximate causes of behaviour. However, understanding the original function of these adaptive responses can help us explain why animals perform apparently novel or functionless activities in certain housing conditions and may help us to appreciate what the animal welfare implications might be. This paper reviews the behavioural adaptation of the domestic horse to captivity and discusses how apparently abnormal behaviour may not only provide a useful practical indicator of specific environmental deficiencies but may also serve the animal as an adaptive response to these deficiencies in an “abnormal” environment.
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von Borstel, U. U., Duncan, I. J. H., Shoveller, A. K., Merkies, K., Keeling, L. J., & Millman, S. T. (2009). Impact of riding in a coercively obtained Rollkur posture on welfare and fear of performance horses. Appl. Anim. Behav. Sci., 116(2-4), 228–236.
Abstract: Rollkur, the usually coercively obtained hyperflexion of the horse's neck, is employed as a training method by some dressage riders; however, its use is controversial as it may cause discomfort and adversely affect the horse's welfare. The objectives of this study were to determine: (1) if horses showed differences in stress, discomfort and fear responses as measured by heart rate and behaviour when ridden in Rollkur (R) obtained by pressure on the reins compared to regular poll flexion (i.e. with the nose-line being at or just in front of the vertical; N), and (2) if they showed a preference between the two riding styles when given the choice. Fifteen riding horses were ridden 30 times through a Y-maze randomly alternating between sides. Riding through one arm of the Y-maze was always followed by a short round ridden in R, whereas riding through the other arm was followed by a short round ridden in N. Immediately after the conditioning phase, horses were again repeatedly ridden into the maze; however, riders left it to the horse to decide which arm of the maze to enter. During R, horses moved slower and showed more often behavioural signs of discomfort, such as tail-swishing, head-tossing or attempted bucks (P < 0.05), and 14 of the 15 horses chose significantly (P < 0.05) more often the maze-arm associated with N rather than R. Subsequently, eight of the horses were also subjected to two fear tests following a short ride in N as well as a ride in R. During R, horses tended to react stronger (P = 0.092) to the fear stimuli and to take longer (P = 0.087) to approach them. These findings indicate that a coercively obtained Rollkur position may be uncomfortable for horses and that it makes them more fearful and therefore potentially more dangerous to ride. Further studies need to assess horses' reaction to gradual training of Rollkur, as opposed to a coercively obtained hyperflexion, in order to decide whether the practice should be banned.
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Baragli, P., Vitale, V., Paoletti, E., Sighieri, C., & Reddon, A. R. (2011). Detour behaviour in horses (Equus caballus). J. Ethol., 29(2), 227–234.
Abstract: The objective of this study was to investigate the ability of horses (Equus caballus) to detour around symmetric and asymmetric obstacles. Ten female Italian saddle horses were each used in three detour tasks. In the first task, the ability to detour around a symmetrical obstacle was evaluated; in the second and third tasks subjects were required to perform a detour around an asymmetrical obstacle with two different degrees of asymmetry. The direction chosen to move around the obstacle and time required to make the detour were recorded. The results suggest that horses have the spatial abilities required to perform detour tasks with both symmetric and asymmetric obstacles. The strategy used to perform the task varied between subjects. For five horses, lateralized behaviour was observed when detouring the obstacle; this was consistently in one direction (three on the left and two on the right). For these horses, no evidence of spatial learning or reasoning was found. The other five horses did not solve this task in a lateralized manner, and a trend towards decreasing lateralization was observed as asymmetry, and hence task difficulty, increased. These non-lateralized horses may have higher spatial reasoning abilities.
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Bentley-Condit, V., & Smith, E. O. (2010). Animal tool use: current definitions and an updated comprehensive catalog. Behaviour, 147(2), 185–32.
Abstract: Despite numerous attempts to define animal tool use over the past four decades, the definition remains elusive and the behaviour classification somewhat subjective. Here, we provide a brief review of the definitions of animal tool use and show how those definitions have been modified over time. While some aspects have remained constant (i.e., the distinction between 'true' and 'borderline' tool use), others have been added (i.e., the distinction between 'dynamic' and 'static' behaviours). We present an updated, comprehensive catalog of documented animal tool use that indicates whether the behaviours observed included any 'true' tool use, whether the observations were limited to captive animals, whether tool manufacture has been observed, and whether the observed tool use was limited to only one individual and, thus, 'anecdotal' (i.e., N = 1). Such a catalog has not been attempted since Beck (1980). In addition to being a useful reference for behaviourists, this catalog demonstrates broad tool use and manufacture trends that may be of interest to phylogenists, evolutionary ecologists, and cognitive evolutionists. Tool use and tool manufacture are shown to be widespread across three phyla and seven classes of the animal kingdom. Moreover, there is complete overlap between the Aves and Mammalia orders in terms of the tool use categories (e.g., food extraction, food capture, agonism) arguing against any special abilities of mammals. The majority of tool users, almost 85% of the entries, use tools in only one of the tool use categories. Only members of the Passeriformes and Primates orders have been observed to use tools in four or more of the ten categories. Thus, observed tool use by some members of these two orders (e.g., Corvus, Papio) is qualitatively different from that of all other animal taxa. Finally, although there are similarities between Aves and Mammalia, and Primates and Passeriformes, primate tool use is qualitatively different. Approximately 35% of the entries for this order demonstrate a breadth of tool use (i.e., three or more categories by any one species) compared to other mammals (0%), Aves (2.4%), and the Passeriformes (3.1%). This greater breadth in tool use by some organisms may involve phylogenetic or cognitive differences � or may simply reflect differences in length and intensity of observations. The impact that tool usage may have had on groups' respective ecological niches and, through niche-construction, on their respective evolutionary trajectories remains a subject for future study.
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Karenina, K., Giljov, A., Ingram, J., Rowntree, V. J., & Malashichev, Y. (2017). Lateralization of mother�infant interactions in a diverse range of mammal species. Nat Ecol Evol, 1, 0030 Ep -.
Abstract: Left-cradling bias is a distinctive feature of maternal behaviour in humans and great apes, but its evolutionary origin remains unknown. In 11 species of marine and terrestrial mammal, we demonstrate consistent patterns of lateralization in mother�infant interactions, indicating right hemisphere dominance for social processing. In providing clear evidence that lateralized positioning is beneficial in mother�infant interactions, our results illustrate a significant impact of lateralization on individual fitness.
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Briard, L., Deneubourg, J. - L., & Petit, O. (2017). How stallions influence the dynamic of collective movements in two groups of domestic horses, from departure to arrival. Behav. Process., 142, 56–63.
Abstract: Abstract The role of leader in polygynous species has been solely attributed to the male for some time, but recent studies shown decision making to be distributed within the group. However, the specific reproductive strategy and behavioural repertoire of males in polygynous species such as horses may mean that these individuals still have the potential to play a specific role during decision-making. To investigate this subject, we thoroughly studied the behaviour of two domestic stallions during collective movements of their group. We found that they initiated rarely and sometimes failed to recruit the entire group. When departing as followers, they did not accelerate the joining process. Both stallions preferentially occupied the rear position and exhibited numerous monitoring behaviours. Herding behaviours were performed by only one stallion and mostly occurred outside movement context. Finally, we removed this herding stallion from its group to evaluate how the group dynamic changed. As a result, half of the collective movements were five times slower and mares were more dispersed in comparison when the stallion was in the group. Overall, our results suggest that, the two stallions maintained their role of group monitors from departure to arrival. Their influence on the movement dynamic was indirect and did not play a specific role in the process of decision making.
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Schwenk, B. K., Fürst, A. E., & Bischhofberger, A. S. (2016). Traffic accident-related injuries in horses. Equine Med., 32(3), 192–199.
Abstract: Horses involved in road traffic accidents (RTAs) are commonly presented to veterinarians with varying types of injuries. The aim
of this study was describe the pattern and severity of traffic accident-related injuries in horses in a single hospital population. Medical
records of horses either hit by a motorized vehicle or involved in RTAs whilst being transported from 1993 to 2015 were retrospectively
reviewed and the following data was extracted: Signalement, hospitalisation time, month in which the accident happened, cause of the
accident, place of the accident and type of vehicle hitting the horse. Further the different body sites injured (head, neck, breast, fore limb,
abdomen, back and spine, pelvis and ileosacral region, hind limb, tail and genital region), the type of injury (wounds, musculoskeletal
lesions and internal lesions) and the presence of neurological signs were retrieved from the medical records. 34 horses hit by motorized
vehicles and 13 horses involved in RTAs whilst being transported were included in the study. Most of the accidents where horses were hit
by motorized vehicles occurred during December (14.7%) and October (14.7%), horses were most commonly hit by cars (85.3%) and the
majority of accidents occurred on main roads (26.5%). In 29.4% of the cases, horses had escaped from their paddock and then collided
with a motorized vehicle. Most of the accidents with horses involved in RTAs whilst being transported occurred during April (30.8%) and
June (23.1%). In 76.9% of the cases the accident happened on a freeway. In the horses hit by motorized vehicles the proximal hind limbs
were the body site most commonly affected (44.1%), followed by the proximal front limbs (38.2%) and the head (32.4%). When horses
were involved in RTAs whilst being transported the proximal fore limbs (61.5%), the proximal hind limbs (53.8%) and the distal hind limbs,
back and head (38.5% each) were the most common injured body sites. Wounds were the most common type of injury in both groups
(85.3% hit by motorized vehicle, 76.9% transported ones). In horses hit by a motorized vehicle 35.3% suffered from fractures, in 20.6%
a synovial structure was involved and in 5.9% a tendon lesion was present. 14.7% suffered from internal lesions and 14.7% showed neurologic
symptoms (40% peripheral, 60% central neurologic deficits). On the other hand, in horses involved in a RTA whilst being transported
30.8% suffered from fractures. There were no synovial structures injured and no tendon injuries were present. Furthermore there were
no internal lesions present and only one horse involved in a RTA showed central neurologic symptoms. Injuries of horses being hit by a
motorized vehicle were more severe than when horses were protected by a trailer and involved in a RTA whilst being transported. The study
has been able to identify the different injury types of traffic accident-related injuries in horses. Awareness of the nature of these injuries is
important, to avoid underestimation of their severity.
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Gaunitz, C., Fages, A., Hanghøj, K., Albrechtsen, A., Khan, N., Schubert, M., et al. (2018). Ancient genomes revisit the ancestry of domestic and Przewalski's horses. Science, 360(6384), 111–114.
Abstract: The Eneolithic Botai culture of the Central Asian steppes provides the earliest archaeological evidence for horse husbandry, ~5,500 ya, but the exact nature of early horse domestication remains controversial. We generated 42 ancient horse genomes, including 20 from Botai. Compared to 46 published ancient and modern horse genomes, our data indicate that Przewalski's horses are the feral descendants of horses herded at Botai and not truly wild horses. All domestic horses dated from ~4,000 ya to present only show ~2.7% of Botai-related ancestry. This indicates that a massive genomic turnover underpins the expansion of the horse stock that gave rise to modern domesticates, which coincides with large-scale human population expansions during the Early Bronze Age.
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