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Effects of repeated regrouping on horse behaviour and injuries
Abstract
Domestic horses are faced with social challenges throughout their lives due to limitations in social contact, space restrictions and frequent changes in social companionship. This is in contrast to natural conditions where horses live in relatively stable harem bands. Currently, little is known about how repeated regrouping affect horse behaviour and welfare, and it is unknown whether horses may adapt to regrouping. In this study, we aimed to investigate the effects of an unstable group structure, caused by weekly regroupings, on behaviour and frequency of injuries in young horses. Forty-five horses were included in the study and were randomly assigned to the treatments; Stable (S; seven groups of three horses) or Unstable (U; eight groups of three horses). The experimental period lasted 7 weeks, during which horses in Stable groups remained in the same group, whereas one horse was exchanged between Unstable groups every week. The groups were kept in 80m×80m grass-covered enclosures and were fed additional roughage on the ground daily. Social interactions were recorded in Unstable groups immediately after each regrouping (30min), and in both Stable and Unstable groups on day 1, 3 and 6 after each regrouping (2×20min/group/day). Injuries were scored by the end of the experimental period. The level of aggression shown by horses in Unstable groups immediately after regrouping was not affected by week (F5,35=0.42, P=0.83), indicating that horses neither habituated, nor sensitized, to repeated regrouping. Compared to horses in Stable groups, more agonistic behaviour was shown by horses in Unstable groups (i.e. non-contact agonistic; F1,65=5.60, P=0.02), whereas there was no treatment effect on other variables. The level of play behaviour appeared, however, to be more variable in Unstable groups. There was a significant effect of week on the level of contact agonistic interactions as well as greeting behaviour, due to a high occurrence in weeks 4–6. Non-contact agonistic interactions constituted the major part of agonistic interactions (66%). Possibly as consequence, no serious injuries were registered and there was no treatment effect (U=184; P=0.11). We conclude that the behaviour of young horses is affected by group management, and that horses appear not to adapt to weekly regroupings.
... Agonistic behaviours are generally low among free-ranging horses (Fureix et al. 2012). In open barns, some risk factors for agonistic behaviour have been identified, such as lack of space, restricted feeding and group composition (Jörgensen et al. 2009, Christensen et al. 2011Flauger & Kreuger 2013;Burla et al. 2016;Majecka & Klawe 2018). Injuries as a result of being kicked by another horse can be severe (Knubben et al. 2008b). ...
... Mixing horses and changing management seem to increase the risk of injuries (Knubben et al. 2008b). Christensen et al. (2011) found that regrouping led to more aggressive behaviour until a new hierarchy was established and that the horses did not seem to become accustomed to constant regrouping. Letting horses familiarise by placing them in boxes next to each other before entering the paddock together seems to decrease the risk of injury (Hartman et al. 2009). ...
... The differences in number of injured individuals between the housing systems in the prospective study might be due to group composition (Majecka & Klawe 2018), regrouping (Knubben et al. 2008b;Christensen et al. 2011), restricted feeding (Benhajali et al. 2009;Jörgensen et al. 2011) or space in the paddock (Majecka & Klawe 2018;Flauger & Krueger 2013). The effect of regrouping on frequency of injured horses was clearly demonstrated in the prospective study. ...
Housing horses in open barns is becoming increasingly popular, with positive effects on social interaction and free movement that can improve horse welfare. However, many horse owners are concerned that group housing may lead to more injuries, less lying time and obesity. This thesis evaluated the effects of group housing horses an active open barn on behaviour and welfare in terms of health, rest and feeding. Horses at the Swedish National Equestrian Centre sites Strömsholm and Flyinge were studied. Health indicators such as lameness and colic were found to be lower for horses kept in the active open barn than in single boxes. Horses in the active open barn had a higher incidence of injuries due to kicks, but this did not lead to more days lost from training. Therefore, concerns about injuries in this system do not appear to be warranted. Comparisons of lying halls with different lying areas revealed that smaller lying halls led to shorter lying times compared with larger lying halls and single boxes. Greater available area in the lying hall also increased lying bouts and use of lying halls. Due to intra-individual variation, four measurements per horse were needed to establish a mean value for forage intake rate. In conclusion, keeping horses in an active open barn affects horse health and lying behaviour. Lameness and colic may decrease, probably due to free movement in the active open barn. To increase lying time among group-housed horses, the space requirement is likely to be larger, not smaller, than in individual boxes.
... As an alternative to single housing, group housing systems are becoming more widely used [18]. However, social contact between individuals always involves the potential of agonistic interactions, which can evoke social stress [7,19]. The occurrence of agonistic encounters depends on various factors such as a horse´s individual experiences, personality, or the composition of the social group in regard to age, sex, and stability [19,20]. ...
... However, social contact between individuals always involves the potential of agonistic interactions, which can evoke social stress [7,19]. The occurrence of agonistic encounters depends on various factors such as a horse´s individual experiences, personality, or the composition of the social group in regard to age, sex, and stability [19,20]. Aggressive interactions often occur during hierarchy establishment after disruption of the existing social structure, for example by changes in group composition [19,20]. ...
... The occurrence of agonistic encounters depends on various factors such as a horse´s individual experiences, personality, or the composition of the social group in regard to age, sex, and stability [19,20]. Aggressive interactions often occur during hierarchy establishment after disruption of the existing social structure, for example by changes in group composition [19,20]. However, due to management requirements, regroupings often have to be applied. ...
Domestic horses are currently often subject to management practices that can entail social stressors, which in turn can negatively influence immunocompetence and disease susceptibility.
The present study therefore aimed to characterize the number of various blood leukocyte subsets in horses, focusing on two potentially stressful housing environments: changes in group composition and relocation to individual stabling. Immune measurements were conducted before as well as one and eight days after changes were made. They were complemented by an assessment of plasma cortisol concentrations as well as behavioral observations. One and eight days after relocation to single housing, the mean numbers of eosinophils, T helper cells and cytotoxic T cells decreased by up to 31%, 20% and 22% respectively, whereas the mean numbers of neutrophils increased by 25%. In contrast, one and eight days after changes in group composition not only the mean number of neutrophils, but also of monocytes, T helper cells and cytotoxic T cells increased by up to 24%, 17%, 9%, and 15% respectively. In consequence, an increase in the neutrophil-to-lymphocyte ratio indicating stress-induced immune modulation was found after relocation to single housing, but not after changes in group composition. The changes in leukocyte numbers after relocation to single housing were accompanied by a transient increase in cortisol concentrations after one day and the occurrence of disturbed behavior patterns one week after change in housing condition. In contrast, changes in group composition did not result in an increase of cortisol concentrations or in an increase of aggressive interactions. The results strongly indicate that individual stabling is an intense stressor leading to acute and lasting alterations in blood counts of various leukocyte types. The study highlights a probable negative impact of single housing on welfare and health of horses and an advantage of group housing systems in view of immunocompetence.
... To succeed in equitation, horses must learn different categories of exercises that are demanded by riders [5]. However, rider weight and posture, as well as the intensity applied to cues, are variable, which often results in differences in the information perceived by the horse [6]. Nevertheless, horses have an incredible behavioural flexibility that allows them to adapt their responses to the intensities of the cues given by different riders [7][8][9][10]. ...
... Competition has been shown to induce physiological modifications in horses related to stress [5][6][7][8][9][10][11]. In competition, riders expect their horses to ignore external stimuli and to perform as usual in response to trained cues, which requires horses to generalise those cues from a training environment to a new context with multiple stimuli, such as the presence of the public [11]. ...
... Horses are requested to generalise their responses to different stimuli over training, either through Hence, the generalisation of a well-known stimulus to different stimuli is a factor in equine management and welfare [5]. This means that providing more efficient and reliable training methods for riders and owners can increase the welfare of horses [6,11]. Therefore, to efficiently improve horse welfare in equine husbandry and training, riders and owners should learn from scientific knowledge instead of following common beliefs [15]. ...
The generalisation of responses to different stimuli depends on the ability to create associations between stimuli. Stimulus
generalisation can be performed for different stimuli or for different contexts in which the same stimulus is perceived. This
study investigated the stimulus-generalisation abilities of horses in different contexts. Sixteen horses were involved in this study.
During the learning activity (LA), horses were given the chance to choose between two geometrical figures (a triangle and a circle)
to obtain a food reward; the circle always corresponded to the correct choice. The rule was considered learned if a horse was
correct more than 70% of the time and made 4 consecutive correct choices. Then, a generalisation test (GT) with ten devices (5
circles, 5 triangles) was created to test generalisation. Only eleven horses respected the learning criteria and were included in the
generalisation test. A significant difference in the number of correct choices between the learning activity and the generalisation
test was observed (Wilcoxon signed-rank test, S=-33; p=0.001; LA: median=6, min=3, max=9; GT: median=3, min=0, max=5). There
was no significant difference in the number of incorrect choices between the two tests (Student’s t test, t=-0.91; DF=10; p=0.384). A
significant difference in the total number of choices between the two tests was observed (Student’s t test, t=2.56; DF=10; p<0.05).
This experiment suggested limits in the capacity of horses to generalise a well-known task in different contexts. Because horses are
often exposed to different environments or contexts, these results provide interesting and applicable knowledge for equine training
and management.
... Likewise, social instability in managed domestic animals can also lead to reduced welfare. In horses (Equus caballus) housed in stable social groups, agonistic behaviour was significantly lower than those housed in unstable social groups [11], and in cattle (Bos taurus) regrouping has led to negative impacts on emotional and physiological wellbeing, health and resistance [12]. Furthermore, stable social groups in goats (Capra aegagrus hircus) has led to the development of affiliative relationships, a reduction in agonistic relationships and increased group cohesion [13]. ...
... Evidence-based social management, based on species knowledge, is extremely important for zoo and domestic animal welfare. Problems arising from unstable or inappropriate social groups have been highlighted in a number of exotic and domestic species including rhesus macaques (Macaca mulatta) [37,38], golden lion tamarins (Leontopithecus rosalia) [39], bottle nosed dolphins (Tursiops aduncus) [40], goats [13], cows [12] and horses [11]. Furthermore, the ability to cater for animal social needs within zoos has been identified as dependent on the species [7]. ...
Zoo animal management procedures which lead to changes to social groups can cause disruption in social hierarchies and the temporary breakdown of social relationships. Animals have different roles in social networks. Understanding individual positions in social networks is important for effective management and ensuring positive welfare for all animals. Using elephants as a case study, the aim of this research was to investigate temporal social dynamics in zoo animals. Behavioural data were collected between January 2016 and February 2017 from 10 African and 22 Asian elephants housed at seven zoos and safari parks in the UK and Ireland. Social interactions were defined as positive physical, positive non-physical, negative physical or negative non-physical. Social network analysis explored social relationships including the fluidity of networks over time and dyadic reciprocity. Social interaction networks were found to be fluid but did not follow a seasonal pattern. Positive interaction networks tended to include the entire social group whereas negative interactions were restricted to specific individuals. Unbalanced ties were observed within dyads, suggesting potential inequalities in relationships. This could impact on individual experiences and welfare. This research highlights subtle temporal dynamics in zoo elephants with the potential for species-level differences. Similar temporal dynamics may also be present in other socially housed zoo species. This research thus provides evidence for the importance of understanding the social networks of zoo animals over longer periods of time. Understanding social networks enables pro-active and evidence-based management approaches. Further research should seek to identify the minimum sampling efforts for social networks in a range of species, to enable the implementation of regular monitoring of social networks and thus improve the welfare of social species under human care.
... Hartmann et al. (2015) reported that over 40% of respondent horse owners expressed concern over injuries in group housing, difficulties with introducing new horses in an existing group, and group feeding. Yet, studies show no higher prevalence of injuries in grouphoused horses (Knubben et al., 2008;Christensen et al., 2011;Keeling et al., 2016;König Von Borstel et al., 2016), despite a higher frequency of agonistic interactions in unstable groups, compared to stable groups (Christensen et al., 2011). Flauger and Krueger (2013) studied 11 groups of domestic horses and found an effect of space allowance on agonistic behavior, especially at higher densities, but frequency and severity of injuries were not measured. ...
... Hartmann et al. (2015) reported that over 40% of respondent horse owners expressed concern over injuries in group housing, difficulties with introducing new horses in an existing group, and group feeding. Yet, studies show no higher prevalence of injuries in grouphoused horses (Knubben et al., 2008;Christensen et al., 2011;Keeling et al., 2016;König Von Borstel et al., 2016), despite a higher frequency of agonistic interactions in unstable groups, compared to stable groups (Christensen et al., 2011). Flauger and Krueger (2013) studied 11 groups of domestic horses and found an effect of space allowance on agonistic behavior, especially at higher densities, but frequency and severity of injuries were not measured. ...
Group housing provides horses with social contact, a lack of which is associated with health and behavior problems. Despite the benefits of group housing for horses, horse owners are concerned about aggression and resulting injuries. This study focused on agonistic and affiliative interactions in a focal group of (originally) 12 horses with short and longer term changes in composition, variation in available area and presence of peri-parturient mares. Age and density had no significant effect on agonistic or affiliative behavior. However, when agonistic behavior was considered within three subcategories, density did have a significant positive effect on contact and threat aggression, but not on passive aggression (avoid and displace). When analyzing only the days without the most aggressive horse, age and density had a positive effect on agonistic interactions, and density had a negative effect on affiliative interactions. Days with and without the most aggressive horse showed no significant overall differences in either category of social interactions. Agonistic and affiliative interactions were not significantly correlated, but agonistic interactions had a significant linear and quadratic effect on affiliative interactions. Relative level of aggressiveness was used instead of a formal measure of dominance rank as aggression level is the main issue for horse owners. Comparing interactions with more and less aggressive horses, there was no overall effect for affiliative interactions. However, overall, horses in the focal group were on average 3.7 times more aggressive towards less aggressive horses, compared to more aggressive horses. Relationships between agonistic and affiliative interactions, density, age and the role of relative aggressiveness are complicated and more research is needed to clarify the most relevant factors under particular sets of circumstances and their contribution to intraspecific aggression in various contexts.
... The results of 2,912 questionnaires sent to horse and pony guardians in Switzerland showed that only less than 1% of all evaluated individuals became lame as a consequence of being kicked by another horse (Knubben, Fürst, Gygax, & Stauffacher, 2008). Also, research by Christensen, Søndergaard, Thodberg, and Halekoh (2011) indicated a low level of injuries of horses kept in groups in a paddock. Likewise, observations of semiferal and feral horses have shown that serious injury inflicted by other individuals is not common (Grogan et al., 2005;Waring, 2003). ...
... It has been proven that regrouping increases the frequency of agonistic and friendly interactions (Christensen et al., 2011;Granquist, Thorhallsdottir, & Sigurjonsdottir, 2012;Knubben et al., 2008). Also, stallions who rejoin a herd after a period of isolation display higher levels of both friendly and aggressive interactions (Christensen et al., 2002). ...
The aim of this study was to explore whether the size of paddocks affected social interactions within a group of horses. Furthermore, the effects of the gender composition in groups on social behavior were investigated. The research was done in a horse-riding center. A total of 78 horses and ponies, forming 3 groups, were included in the study. The time of the observation was divided into 2 periods. The data obtained from the 1st period (the horses were on relatively small paddocks) and the 2nd period (the paddocks were significantly bigger) were compared. The findings uniformly indicated that an enlargement of grass paddocks resulted in a significant decline in the number of social interactions, both agonistic and play types, in all studied herds. A likely principal reason for a change in the number of social interactions seems to be feeding management and how it changed between seasons, rather than paddock size. No effect of group composition on social interaction was found in terms of aggressive interaction, and only 1 group differed regarding friendly interaction.
... social hierarchy within the group (Knubben et al. 2008;Hartmann et al. 2009;Christensen et al. 2011). However, the frequency of aggressive interactions varies between horses (Christensen et al. 2011) and most of the interactions that normally occur between recently grouped horses on pasture, where they have more space than that provided in a trailer, do not result in a high prevalence of injury (Jørgensen et al. 2009;Hartmann et al. 2011). ...
... social hierarchy within the group (Knubben et al. 2008;Hartmann et al. 2009;Christensen et al. 2011). However, the frequency of aggressive interactions varies between horses (Christensen et al. 2011) and most of the interactions that normally occur between recently grouped horses on pasture, where they have more space than that provided in a trailer, do not result in a high prevalence of injury (Jørgensen et al. 2009;Hartmann et al. 2011). The prevalence of injury in many loads was greater than that seen in non-transported horses. ...
Horses transported in groups on long journeys to slaughter are at risk of injury. Injuries can occur following trauma and aggression from other horses. This study quantified injuries in 3940 horses from 150 loads that arrived at a slaughter plant in Canada. Surface injuries were quantified using visual assessment. Digital thermography was used to detect areas of raised surface temperature. Carcasses were assessed for bruising. Multivariable regression analysis was used to examine the associations between journey characteristics and the risk of injury. There was a significant association between journey duration and the number of horses per load with surface injuries (P<0.001). In 100 horses from 40 loads studied in detail, 33% had surface injuries identified by visual assessment, 48% had areas of raised surface temperature identified by thermography and 72% had bruising identified by carcass assessment. The levels of agreement between identification of injury by thermography and that by identification of visible injuries and carcass bruising were low. Pre-transport assessments could not be performed and hence injuries could not be linked causally to the transport conditions alone. However, the detailed assessments of injury and the use of multivariable regression analysis showed that long journeys were associated with injuries.
... Previous research has found that group housing accommodates the physical, behavioral and social needs of horses in ways that solitary housing does not 57,64,65 , and group housing improves interactions between humans and horses during training 66,67 . When experimental conditions permit, therefore, horses should be housed in groups, and there are various methods that accomplish this 63,68,69 . ...
... When an aggressor is very motivated or when two horses of comparable strength are sparring, an aggressive horse can break even a sturdy fence, which can injure horses and damage the housing facility 32 . Aggressive interactions most commonly arise in group housing when group composition is unstable 1 , and regrouping of young horses has been shown to increase the frequency of agonistic interactions and decrease the frequency of positive social interactions 65 . Overstocked facilities, poor facility design, insufficient resources and inadequate resting times can also promote aggressive behaviors in some horses 70 . ...
Horses and ponies are used for experimental research in a variety of fields, but there is little published scientific literature that describes current or evidence-based recommendations for keeping and managing these species for research purposes. Equine species require particular environmental conditions and allowances to accommodate their behavior and physiology. Here the authors review studies and common practices for ambient facility conditions; provision of bedding, food and water; opportunities for exercise and environmental enrichment; allocation of facility spaces and resources; and design and management of different stabling systems for horses and ponies in research. Careful consideration of these factors can help to improve the welfare of equine subjects in research and to ensure high-quality experimental data.
... In pigs, for example, different studies have documented consistent individual differences in aggressiveness towards meeting unfamiliar conspecifics (D'Eath, 2002;Hessing et al., 1993). In horses, Christensen et al. (2011) andHartmann et al. (2009) showed that some individuals acted more aggressively than others towards meeting conspecifics. Being able to identify these characteristics could benefit individuals by adjusting mixing methods, especially for those horses that are less flexible in their responses to changes of social partners. ...
... On the contrary, this was not supported by Raussi et al. (2006) who observed that repeated grouping of heifers consistently induced agonistic interactions. In a study by Christensen et al. (2011), group membership was shifted every week. The horses did not seem to become accustomed to this repeated grouping as no significant reduction of aggressive encounters was observed with increasing number of grouping events. ...
Although husbandry conditions for horses have improved over the last decades, many horses are still kept singly with limited or no physical contact to other horses. This is surprising, given the fact that keeping horses in groups is recognised best to fulfil their physical and behavioural needs, especially their need for social contact with conspecifics, as well as to have a beneficial effect on horse–human interactions during training.Group housing of farm animals is widely applied in practice. As a consequence, scientists have investigated numerous aspects of group housing to help further improve animal welfare and human–animal interactions under these conditions. However, compared to this literature available in farm animals, and the plentiful studies conducted of feral horse populations, there is much less done when it comes to the management of horses kept in groups in the domestic environment. In particular, limited scientific information is available into the effect of group size and group composition on behaviour and methods of introducing new horses into established groups, even though problems related to social integration are repeatedly taken as arguments against keeping horses in groups.This review, therefore, aims to provide an overview of the current scientific knowledge regarding keeping horses in groups. Furthermore, it aims to give insight into whether or not some of the concerns related to keeping horses in groups are justified and to review scientifically based solutions that could be useful in practice to improve horse welfare and human safety.
... Although some scarring or hair loss was seen from tethering, few mules had open wounds from this practice, which could indicate that the materials being used were fit for purpose such as being soft, wide, breathable, clean and correctly tensioned. It could also be an indication of the settled social structure of the groups tethered together (Christensen et al., 2011;Fureix et al., 2012) or a lack of salient resources (food, water, mares) to compete over (Pierard et al., 2019), which would reduce aggressive and associated avoidance interactions meaning straining at tethers was minimised, this is corroborated by the lack of conspecific bite injuries seen during assessments. Companion bonding was highlighted by some owners as being important for their mules, appreciating that some mules worked better or kept in close contact with specific mules. ...
Working equid populations are mainly present in low to middle-income countries, their work directly contributing to the lives of people reliant on their presence. Although assistance from working equids is important to support people and their communities in these regions, their welfare is often poor. This study aims to provide insight into the welfare status of mules distributing supplies in the Gorkha region of Nepal; a population of working equids which has been largely overlooked and under recorded. The welfare of mules was assessed via the Equid Assessment Research and Scoping (EARS) tool using a trained assessor; livelihood surveys gathered basic demographic and ownership information; and semi-structured interviews gained the perspectives of 26 key informants. Mule body condition was found to be ideal in many cases, but their management was in the majority of cases inappropriate; characterised by integumentary trauma from equipment use and inhumane handling, unsuitable dietary provision, and insufficient access to water. This difficult situation was compounded by inadequate access to suitably qualified, experienced veterinary professionals able to offer appropriate levels of support. Organisations aiming to improve welfare in these remote locations need a multifaceted approach where owners are facilitated and empowered to improve the welfare of their own equids; in addition, industry professionals are encouraged to improve training and provision within veterinary services.
... This could be linked to more time and space to engage in grazing, resting, and other natural behaviors if resources are restricted in confined areas. Agonistic behaviors have also been seen more frequently in groups of horses that are socially unstable [48], suggesting that higher stocking densities and smaller spaces result in higher frequency of social interactions. Furthermore, agonistic behaviors have been linked to space sharing and choices of closest conspecifics [13,16,49,50], suggesting that both agonistic and affiliative behaviors may increase in more confined areas and higher stocking density. ...
Studies show that horses express favoritism through shared proximity and time and demonstrate unique affiliative behaviors such as allogrooming (mutual scratching) with favorite conspecifics. Allogrooming also occurs more frequently during stress and has been observed to occur more frequently in domestic herds than feral. The role of partner preference, lateralization, and duration of allogrooming as measures of social bonding has remained unclear. The present study looked at two socially stable herds of mares (n = 85, n = 115) to determine the frequency, duration, visual field of view and partner preference during allogrooming in both pasture settings (low stress) and confined settings (higher stress). One hundred and fifty-three videos for both herds were coded for allogrooming behaviors with 6.86 h recorded in confined conditions and 31.9 h in pasture settings. Six allogrooming sessions were observed in the pasture setting with an average duration of 163.11 s. In confined settings, a total of 118 allogrooming sessions were observed with an average duration of 40.98 s. Significant (p < 0.01) differences were found between settings for duration (s), number of allogrooming pairs, and frequency of allogrooming (per min) for each herd. All observed allogrooming sessions involved pairs of favored conspecifics (one partner per horse). The current study suggests that horses may have friendships that can be observed through the demonstration of specific affiliative behaviors during times of stress with more frequent, but shorter affiliative interactions with preferred partners during times of stress. This context suggests that horses adhere to the “tend and befriend” principles of friendship in animals.
... Cependant, cette théorie manque de crédibilité car, à part des récits anecdotiques, ces aspects du comportement social des équidés n'ont jamais été enregistrés. Des études éthologiques montrent que les leaders dans la société équine sont rarement les individus les plus agressifs ou dominants (Tyler, 1972), que la société équine est matriarcale, basée sur des associations à long terme entre des individus apparentés et des compagnons préférés (VanDierendonck & Spruijt, 2012), et que la réponse habituelle à l'agression est l'évitement (Christensen et al., 2011). De plus, la réconciliation dyadique et les interactions affiliatives post-conflit avec des tiers constituent des mécanismes sociaux importants pour la gestion des situations post-conflit chez les chevaux (Cozzi et al., 2010). ...
Ce projet de thèse vise à étudier la pertinence d’utiliser la médiation équine en thérapie, auprès de personnes ayant des troubles addictifs. Dans un premier temps, il s’agira d’étudier l’influence du style d’attachement des patients sur leur niveau d’autonomie ; en s’appuyant sur des modèles théoriques tels que la théorie de l’attachement (Bowlby, 1969-82 ; Hazan, 1987) et la théorie de la motivation autonome (Decy et Ryan, 2000). Dans un deuxième temps, l’objectif sera d’explorer, de décrire et d’évaluer les processus à l’œuvre durant l’intervention à visée thérapeutique avec le cheval. Cette recherche s’inscrit dans le cadre de la compréhension et de l’évaluation des interventions complexes, axe fort de recherche du laboratoire APEMAC. Le questionnement principal de ce projet de thèse est d'interroger la place de la théorie de l’attachement dans les interventions en psychologie de la santé, notamment dans les programmes de prévention de la reconsommation et de la rechute. Quels liens la motivation et l’attachement entretiennent-ils ? En quoi les troubles de l’attachement peuvent-ils entraver le processus de guérison et la tenue de l’abstinence chez ces patients ? L’utilisation du cheval en thérapie peut-elle permettre d’augmenter le sentiment de sécurité interne des personnes et favoriser le développement de leurs compétences d’auto-régulation et de la motivation autonome ? En somme, peut-on augmenter l’autonomie des patients en leur proposant une intervention qui cible les troubles de l’attachement ? Le recueil des données sera réalisé au Centre de Soins de Suite et de Réadaptation en Addictologie « la Fontenelle ». Tout au long de cette recherche, nous prévoyons d’effectuer différentes évaluations quantitatives à l’aide d’outils psychométriques. Nous utiliserons également des méthodes qualitatives en réalisant des entretiens cliniques.
... Many studies in horse social interactions often focus on these repulsion signals, emphasizing agonistic and dominance behaviors over potential affiliative responses. Such studies often focus exclusively on the agonistic behaviors between domestic (rather than feral) horses [10,11] emphasizing the pinning of ears, kicking, baring teeth, and larger behaviors where horses might bite, kick, or chase each other. Studies in horses have also focused on the concept of social hierarchy with emphasis on looking at agonistic behaviors as a means of assessing "dominant" horses within a herd [12][13][14]. ...
Recent research in equine pro-social behavior has shifted from agonistic and aggressive behaviors to a greater emphasis on affiliative interactions. With increased prioritization of physiological and psychological welfare in horses, studies have begun to focus not only on understanding stress behaviors, but also how to improve recognition of positive emotional affects in equine behaviors and the contexts in which they take place. Previous research in affiliative interactions focused on proximity and allogrooming as indicators of affiliative bonds between horses and can be used as a foundation for studying additional affiliative interactions that are exclusive between bonded pairs. This study is a preliminary investigation of behaviors exhibited between twelve bonded pairs of quarter horse mares of reproductive age living in large, socially stable herds. The goal of this study is to create a preliminary list of behaviors that occur exclusively between horse friends that indicate behavioral demonstrations of affection. Researchers used proximity indicators to identify bonded pairs and focused on coding behaviors that horses voluntarily expressed with their chosen friends and not with other mares. Researchers used video data to log and count behaviors within and between pairs to look for differences in individual preferences for affiliative interactions (whether presenting or receiving) and to determine any differences between how each pair exhibits affiliative interactions. Behaviors observed included initiation of allogrooming, touching body with nose, deliberately moving head over or under the head and neck of their partner, placing head over the back of partner, and moving to closer proximity. All twelve pairs demonstrated behaviors of initiating closer proximity indicating affiliative preference. Each pair also exhibited at least two other affiliative behaviors with only one pair partaking in allogrooming behavior. Individuals within pairs also differed in their preferred affiliative interactions, suggesting that individual horses have unique preferences for expressing and receiving affiliative behaviors which may differ from their partner's preferences. This study can serve as a preliminary foundation for examining how horses choose to demonstrate affection and can inform interpretations of psychological welfare in horses and provide new insights into horse-human interactions.
... Recorded interactions were divided into four categoriesagonistic (head-threat, kick-threat, kick, bottom pushing, chasing, displacement), friendly (nose-nose contact, sniffing, nibbling/licking, grooming), playful (sexual, locomotive, play-fighting) and snapping, compiled according to Araba and Crowell-Davis (1994), Christensen et al. (2011), McDonnell (2003. For ethogram used see Supplementary file 2. Initiators and recipients of all interactions were recorded. ...
Paternal care in mammals can have a wide range of displays. Stallions mostly invest in their offspring indirectly through herd defense and occasional play with the foals, but until recently this relationship had not been analyzed thoroughly. Recent research in semi-feral horses revealed unique social interactions between offspring and their sire, highlighting different attitude of mares and stallions toward the foals and vice versa. Here we present subsequent research focused on the variability of foals' behavior under different social context. Two herds of semi-feral Exmoor ponies in 3 different types of social groups were observed: SMF - stallion + mares + foals (under 1y of age) (1+14+13; 1+14+8, season 2016 and 2017), SMYF - stallion + mares + young (1–2y, both sexes) + foals (1+13+9+10; 1+14+10+13, season 2018) and MYF - mares + young (1–2y females only) + foals (14+6+11; 20+13+18, season 2020). Each type of group was observed for one season, approximately from April to October every 2 weeks (748 h and 8473 interactions in total, all observed years). All herd members were observed directly, by ad libitum sampling method, during sessions lasting 2–4 h throughout the daylight. Differences in the frequencies (χ² test) of 4 groups of behavior were calculated (friendly, agonistic, social play and snapping). Probabilities of occurrence in foal's behavior were studied through GLMM considering the effects of sex (colts vs. fillies), type of herd, and type of receiver of the interaction. The results show, that SMYF groups had lower aggressive (P = 0.003) and social play (P < 0.001) frequency than the other groups, but higher frequency of friendly and snapping behaviors (both P < 0.001). MYF groups showed significant drop in snapping (P < 0.001) and increase in social play (P < 0.001) frequency. For each social system studied, foals consistently preferred their peers for friendly and playful interactions over adults and young. However, fillies preferred colts as play partners over other fillies only when the stallion was present, while in herds with no stallion they significantly switched to same-sex partners. On the contrary, the behavior of foals to mares was constant in all 3 types of groups. The different social context of herds clearly influenced the behavior of the foals. One of the most notable outputs of this study is the influence of stallion presence on fillies’ behavior. The results indicate that the behavior of both sons and daughters may change when they grow up in groups without a father, which is highly relevant considering that these conditions are common in domestic horses’ husbandry.
... While reference [74] determined that gender, reproductive status and type of enclosure influence the time budget of Przewalski horses, in domestic horses influences due to the management are likely. With this, feeding [10,70], the provision of fresh straw or other enrichment material [75], regrouping [76] or cleaning could be named. Looking at the results, the number of cliques with more than six horses as well as the density showed highest means for the hour 8 a.m. to 9 a.m., and the medians and means of the diameter values grouped by hours reached the minimal values. ...
Sensors delivering information on the position of farm animals have been widely used in precision livestock farming. Global Positioning System (GPS) sensors are already known from applications in military, private and commercial environments, and their application in animal science is increasing. However, as trade-offs between sensor cost, battery life and sensor weight have to be made, GPS based studies scheduling long data collection periods and including a high number of animals, have to deal with problems like high hardware costs and data disruption during recharging of sensors. Furthermore, human–animal interaction due to sensor changing at the end of battery life interferes with the animal behaviour under analysis. The present study thus proposes a setting to deal with these challenges and offers the software tool “HerdGPS-Preprocessor”, because collecting position data from multiple animals nonstop for several weeks produces a high amount of raw data which needs to be sorted, preprocessed and provided in a suitable format per animal and day. The software tool “HerdGPS-Preprocessor” additionally outputs contact lists to enable a straight analysis of animal contacts. The software tool was exemplarily deployed for one month of daily and continuous GPS data of 40 horses in a loose-housing boarding facility in northern Germany. Contact lists were used to generate separate networks for every hour, which are then analysed with regard to the network parameter density, diameter and clique structure. Differences depending on the day and the day time could be observed. More dense networks with more and larger cliques were determined in the hours prior to the opening of additional pasture.
... The degree to which transfer, birth and death events negatively impact individual elephants likely is influenced by social factors (e.g., group dynamics, relatedness, how long individuals have been together). Coping with stressful events is aided by the presence of supportive conspecifics or can be compromised by poor social situations (Baranyi et al., 2005;Christensen et al., 2011;Bartolomucci et al., 2001;Ljungberg and Westlund, 2000). Recently, Brown et al. (2016) found that female African elephants that spent time in a greater number of different social groups had increased odds of being hyperprolactinemic, and that social isolation, either with or without the ability to interact with herd mates through a barrier, was associated with an increased risk of ovarian acyclicity. ...
Hyperprolactinemia is an endocrine disorder associated with infertility in many species, including elephants. In a recent survey of zoos accredited by the Association of Zoos and Aquariums (AZA), over half of African elephant females (N = 101) were not cycling normally, 30% of which exhibited hyperprolactinemia. We examined whether life experience and temperament predict ovarian cyclicity and circulating prolactin status in individual African elephant females. We hypothesized that, similar to humans, acyclicity and hyperprolactinemia in elephants will be associated with an apprehensive or fearful, anxious temperament, and an increased number of potentially challenging life events (transfers, deaths and births). Ninety-five adult African elephant females housed at 37 AZA institutions were included in this study. Blood samples were collected twice a month for 1 year to determine ovarian cycle (cycling, n = 44; irregular, n = 13; non-cycling, n = 38) and prolactin (normal, n = 44; low; n = 23; high; n = 28) status. Keeper ratings on a 6-point scale were obtained on 32 temperament traits in 85 of these elephants. We determined that giving birth and being exposed to herd mates entering the facility were positively associated with normal ovarian cycle and prolactin profiles. By contrast, age, serum cortisol, and an increased number of herd mates leaving a facility were negatively associated with both. Contrary to our hypothesis, hyperprolactinemia was associated with a popular and caring temperament rating, whereas consistently low prolactin was associated with a fearful, apprehensive temperament. These findings indicate that pituitary-ovarian function may be impacted by life history (cyclicity) and temperament (prolactin), which should be taken into consideration when making management decisions.
... Recorded interactions were divided into four categoriesagonistic (head-threat, kick-threat, kick, bottom pushing, chasing, displacement), friendly (nose-nose contact, sniffing, nibbling/licking, grooming), playful (sexual, locomotive, play-fighting) and snapping, compiled according to Araba and Crowell-Davis (1994), Christensen et al. (2011), McDonnell (2003. For ethogram used see Supplementary file 2. Initiators and recipients of all interactions were recorded. ...
Different forms of direct paternal investment have been described in mammals. One such species where paternal care was noticed, but remains poorly understood, is the horse (Equus caballus), where the male keeps a long-term relationship with several females and offspring. Therefore, the aim of this study was to analyse the interactions between the harem stallion and his foals. Two herds of Exmoor ponies living under semi-feral conditions in two separate reserves within Czech Republic were studied, each during one of the two consecutive breeding seasons (in 2016 and 2017). Both herds consisted of a stallion, 14 mares and their offspring (12 and 10 foals). The behaviour of all group members was recorded focusing on the stallion–foal interactions. The results show that the stallion receives more friendly interactions, snapping and playful behaviour from foals compared with adult mares. Furthermore, the stallion is more tolerant than mares, and actively plays with his offspring. There is no statistical difference in the sex of the foals in the stallion–foal interactions; however, male foals are more active than female foals in interacting with their father. The probability of a certain behaviour occurring between adult and foals changed over time. The stallion’s presence might, therefore, be crucial for the physical and psychological development of the foals, especially the colts. These results may bring new insight into the common management of domestic horses, where stallions are usually kept separately and are not allowed to form natural groups.
... Regarding the equines' opportunity to perform normal behaviors, it is important to guarantee an adequate space allowance to prevent aggressive reactions that might lead to stress competition for resources and for hierarchy establishment with consequent physical injuries. Indeed, wild horses live in relatively stable harem bands, so the overcrowding and the high rates of regrouping of intensively farmed horse may cause an increase in aggressiveness and injuries [20]. On the contrary, in nature, donkeys adapt easily, and their social organization depends on the availability of food and water resources. ...
... Group cohesion is enhanced by affiliative behavioural interactions such as mutual grooming, the latter having been shown to reduce heart rate, a sign of relaxation and positive affect (Feh and De Mazières, 1993). In contrast, social instability can result in increased inter-individual aggression (potentially resulting in negative valence, high arousal states), as demonstrated in young domestic horses that were repeatedly re-grouped (Christensen et al., 2011). When assessing equine husbandry, the relationship between social grouping and equine emotional state is an important factor (Van Dierendonck and Spruijt, 2012) and offers an additional perspective on ways to improve equine welfare (Špinka, 2012). ...
... Group cohesion is enhanced by affiliative behavioural interactions such as mutual grooming, the latter having been shown to reduce heart rate, a sign of relaxation and positive affect (Feh and De Mazières, 1993). In contrast, social instability can result in increased inter-individual aggression (potentially resulting in negative valence, high arousal states), as demonstrated in young domestic horses that were repeatedly re-grouped (Christensen et al., 2011). When assessing equine husbandry, the relationship between social grouping and equine emotional state is an important factor (Van Dierendonck and Spruijt, 2012) and offers an additional perspective on ways to improve equine welfare (Špinka, 2012). ...
The scientific study of animal emotion has recently become an important focus for animal behaviour and welfare researchers. For horses used by humans for work, recreation or sport, the question of the significance of their life experiences in terms of their emotional response, is an important one if we are to provide for their welfare needs. Horses have received relatively less scientific attention than many livestock species when it comes to investigating emotional state or affective experience, although their behavioural responses during sporting or recreational performance are often described anecdotally using terminology indicating an underlying presumption of equine emotions. Indeed, the international governing body for equestrian sport, the Fédération Equestre Internationale (FEI), include the concept of ‘the Happy Equine Athlete’ into their rules, as a key objective during training and competition.
This review presents available evidence to date of the physiological, behavioural and cognitive components of equine emotion and evaluates the extent to which the question concerning ‘how horses feel’ can be answered. The characterization of equine emotion in terms of level of arousal and valence, based on physiological, behavioural and cognitive indicators, offers a way forward to determine the impact of different situations and experiences on horses during their working lives. There is a need to develop robust validated methods for accessing equine emotions, to underpin a universally agreed method for/approach to providing an accurate assessment of equine welfare that can be utilized in a variety of contexts. This will provide a means of monitoring and improving the horse’s experience, ensuring that the horse enjoys a good life, rather than one that is just worth living.
... around day 75 of age [25]) are often attacked by resident males [24]. In addition, amounts of social interactions and levels of aggressive behaviour are significantly heightened at times of socially unstable conditions [26][27][28][29] mainly due to the lack of stable social structures as, for instance, dominance hierarchies and social bonds between animals of the same social unit. Behaving inconspicuously by showing a juvenile behavioural profile and developing more slowly in the presence of resident adult males might decrease the risk of fights and fatal injuries for adolescent UE-sons in unstable social environmental conditions. ...
Background
The social environment the mother experiences during pregnancy and lactation can powerfully influence the offspring’s behavioural profile. Our previous studies in wild cavies show that two different social environments during pregnancy and lactation bring about different behavioural strategies of male offspring later in life: An unstable social environment leads to a behavioural camouflage strategy, hypothesised to be beneficial at times of socially challenging situations. A stable social environment during early phases of life, however, leads to an early reproduction strategy, expected to be more successful at times of social stability. In the present study, we observed the behavioural strategies of the two types of males in direct comparison in a socially challenging situation: Two adolescent males were placed simultaneously in an unknown social group consisting of one adult male and two females in a semi-naturalistic environment. Cortisol as well as testosterone concentrations and activity levels were compared. Furthermore, paternities were analysed after the males reached sexual maturity. We hypothesised that sons showing a behavioural camouflage strategy are better adapted to cope with this socially challenging situation compared to those displaying an early reproduction strategy.
Results
At the beginning of the experiment, no differences in plasma cortisol concentrations between the males were found, both showed a highly significant increase due to the challenging situation. From day 5 until the end of the experiment (duration = 40 days) sons showing an early reproduction strategy had significantly higher plasma cortisol concentrations compared with those showing a behavioural camouflage strategy. Plasma testosterone concentrations did not differ significantly. Activity levels decreased significantly over time independently of the male’s behavioural strategy. Both types of males did not sire offspring during the observation period.
Conclusion
Higher cortisol values from day 5 until the end of the experiment in sons showing an early reproduction strategy indicate higher levels of stress in these males compared to those displaying a camouflage strategy. We conclude that the modulation of the males behavioural strategy due to an unstable social environment during early development facilitates the endocrine adaptation to a comparable social situation later in life.
... Further, we predicted fewer injuries with a stable composition of group members and in groups with horses of different ages and sexes, related to the presumed less time needed to establish and maintain dominance relationships. Parts of these data have been presented previously (Christensen et al., 2011;Jørgensen et al., 2009), but this is the first time all data has been combined in a single analysis. ...
There is increasing interest in keeping horses in groups, but progress is hampered by a lack of knowledge about which horses can and should be kept together. Therefore, our objective was to investigate the effect of group composition on the occurrence of injuries among horses, the ease of removing horses from groups and horses’ reactivity to a fearful stimulus. Using a matched case control design, 61 groups of horses were studied in Denmark, Norway, Finland and Sweden. They were allocated into groups of similar or different age and sex or where membership changed regularly or remained stable. Injuries were recorded before mixing the horses into treatment groups, the day after mixing and four weeks later. Reactivity of horses to a moving novel object and the behaviour of a horse being removed from its group and the reactions of other group members towards this horse and the handler were evaluated. It was hypothesized that a more socially variable group composition has beneficial effects on behaviour, ease of handling and reducing reactivity whereas frequent changes in group composition has negative consequences, resulting in more injuries. We found that differences in treatment effects were mainly related to breed, rather than group composition. Icelandic horses reacted less to the movement of the novel object (P = 0.007) and approached it more afterwards (P = 0.04). They also had fewer new injuries than warmbloods following mixing (P < 0.001) and fewer than all other groups 4 weeks later (P < 0.01). Most new injuries after mixing were minor and recorded on the horse’s head, chest, hind legs and rump. In conclusion, variations in sex and age composition of the group had little effect on injury level, reactivity and ease of handling compared to the general effect of breed. Concerns about the risk of severe injuries associated with keeping horses in groups are probably overestimated. Thus, we propose that horses can be successfully kept in groups of different sex and age composition.
... Change of ownership may have a number of consequences for the horse including change in management regime, training regime, environment and social environment. Horses do not appear to habituate to regular social regroupings [54] suggesting that even without considering associated changes in environment and routine, changes in ownership, or changes in home environment within ownerships, are likely to be stressful for the horse. In order to advance our understanding of equine welfare problems facing horses in GB there is a need to fully explore the number of horses that are affected by all of the contexts raised by the interviewees and the specific welfare consequences for horses in GB. ...
Despite growing concerns about the welfare of horses in Great Britain (GB) there has been little surveillance of the welfare status of the horse population. Consequently we have limited knowledge of the range of welfare problems experienced by horses in GB and the situations in which poor welfare occurs. Thirty-one in-depth interviews were conducted with a cross -section of equine stakeholders, in order to explore their perceptions of the welfare problems faced by horses in GB. Welfare problems relating to health, management and riding and training were identified, including horses being under or over weight, stabling 24 hours a day and the inappropriate use of training aids. The interviewees also discussed broader contexts in which they perceived that welfare was compromised. The most commonly discussed context was where horses are kept in unsuitable environments, for example environments with poor grazing. The racing industry and travellers horses were identified as areas of the industry where horse welfare was particularly vulnerable to compromise. Lack of knowledge and financial constraints were perceived to be the root cause of poor welfare by many interviewees. The findings give insight into the range of welfare problems that may be faced by horses in GB, the contexts in which these may occur and their possible causes. Many of the problems identified by the interviewees have undergone limited scientific investigation pointing to areas where further research is likely to be necessary for welfare improvement. The large number of issues identified suggests that some form of prioritisation may be necessary to target research and resources effectively.
... The risk of injury in horses remains one of the main concerns among respondents (44.9%), which has also been cited in other publications (Fürst, 2013). However, the rate of kick or bite injuries caused by another horse may be relatively low compared with other injuries or health disorders (Knubben et al., 2008a;Derungs et al., 2004) and has not been of any concern in groups of horses studied under controlled conditions (Christensen et al., 2011;Jørgensen et al., 2009;Mejdell et al., 2010). Contrary to the high percentage of respondents being concerned about injury risk in horses, the majority of respondents (65.9%) did not see the necessity to remove shoes from horses turned out in groups, although injury caused by a kick from another horse wearing shoes may be more severe (Knubben et al., 2008a). ...
Keeping horses in groups is widely recommended but limited information is available about how this is implemented in practice. The aim of this survey was to describe how horses are kept in the Nordic countries in relation to sex, age, breed, and equestrian discipline and to assess owners’ attitudes toward keeping horses in groups. Horse owners in Denmark, Finland, Norway, and Sweden were approached using a web-based questionnaire, which was translated into 4 languages and distributed online via equestrian forums, organizations, and social media. The number of respondents was 3,229, taking care of 17,248 horses. Only 8% of horses were never kept in groups, 47% were permanently grouped for 24 h/d, and 45% were stabled singly but grouped during turnout. Yearlings were most often permanently kept in groups (75%), mares and geldings more commonly during parts of the day (50 and 51%, respectively), and stallions were often kept alone (38%). Icelandic horses were more likely to be permanently kept in groups (36%) than warmbloods (16%) and ponies (15%). Twice as many competition horses (51%) were never grouped compared with horses used for breeding (20%) or leisure purposes (15%). The majority of respondents (86%) strongly agreed that group housing benefits horse welfare and that it is important for horses to have the company of conspecifics (92%). Nevertheless, not all horses were kept in groups, showing that attitudes toward group housing may not necessarily reflect current management. The risk of injury was a concern of many respondents (45%), as was introducing unfamiliar horses into already established groups (40%) and challenges in relation to feeding in groups (44%). Safety of people (23%) and difficulties handling groupkept horses (19%) were regarded as less problematic. Results suggest that the majority of horses have the possibility to freely interact with other horses, either as fulltime members of a group during 24 h/d or during turnout. Future research should address the extent to which being a part-time member of a group affects horse welfare. For permanent group housing to become more widespread, such as it is the case for most farm animals, future research could focus on solving some of the reoccurring problems perceived with keeping horses in groups. The dissemination of evidence-based information on all aspects around keeping horses in groups can ultimately stimulate further positive changes in the management of group-kept horses. © 2015 American Society of Animal Science. All rights reserved.
... For example, the birth of offspring can add to the dynamic nature of group interactions by increasing play [1] and the expression of nurturing behaviors [2,3]. Disrupting stable social groups by adding or removing individuals via birth, death, or translocation can cause social instability and increased aggression [4,5,6], resulting in elevated glucocorticoid levels [6,7,8] and subsequent immunosuppression [8,9,10] of group members. For offspring, premature separation from the mother, either through death or translocation, has been associated with increased short-term anxiety and stress [11], as well as longer-term effects such as poorer social skills [12,13] and the development of abnormal (stereotypic) behaviors [14]. ...
This study quantified social life events hypothesized to affect the welfare of zoo African and Asian elephants, focusing on animals that were part of a large multi-disciplinary, multi-institutional elephant welfare study in North America. Age was calculated based on recorded birth dates and an age-based account of life event data for each elephant was compiled. These event histories included facility transfers, births and deaths of offspring, and births and deaths of non-offspring herd mates. Each event was evaluated as a total number of events per elephant, lifetime rate of event exposure, and age at first event exposure. These were then compared across three categories: species (African vs. Asian); sex (male vs. female); and origin (imported vs. captive-born). Mean age distributions differed (p<0.05) between the categories: African elephants were 6 years younger than Asian elephants, males were 12 years younger than females, and captive-born elephants were 20 years younger than imported elephants. Overall, the number of transfers ranged from 0 to 10, with a 33% higher age-adjusted transfer rate for imported African than imported Asian elephants, and 37% lower rate for imported females than males (p<0.05). Other differences (p<0.05) included a 96% higher rate of offspring births for captive-born females than those imported from range countries, a 159% higher rate of birthing event exposures for captive-born males than for their imported counterparts, and Asian elephant females being 4 years younger than African females when they produced their first calf. In summarizing demographic and social life events of elephants in North American zoos, we found both qualitative and quantitative differences in the early lives of imported versus captive-born elephants that could have long-term welfare implications.
... Hestene er ikke i luftegård 1 (0,0 %) 1 (0,0 %) 0 (0,0 %) 1 (0,0 %) (6,7,8,9). Utebokser er en vanlig oppstallingsmåte blant annet i England, men bare 2.5 % av respondentene i vår undersøkelse benyttet denne oppstallingsformen for sin hest. 1,3 % av respondentene svarte at hesten ble holdt i et utegangssystem om vinteren uten tilgang leskur/ bygning, men med naturlig beskyttelse fra skog. ...
Våren 2014 ble det utarbeidet en spørreundersøkelse til norske hesteeiere som tok for seg spørsmål om oppstalling, luftegårder og beite. Undersøkelsen ble spredt via internett og ble besvart av totalt 2075 personer som drev med hest. Hele 27,5 % oppga at hestene ble holdt i løsdrift/utegang, mens 53,6 % oppga at hestene ble holdt i isolert stall og 16,5 % oppga uisolert stall. Majoriteten av hestene (53,1 %) som ble holdt i tradisjonelle staller var i luftegård 5 – 10 timer pr. dag og 35,0 % var i luftegård > 10 timer pr. dag. På vinterstid ble 35,3 % hestene som stod i tradisjonell stall eller utebokser holdt i luftegårder som var < 300 m2. Blant hestene som stod i tradisjonell stall eller utebokser var det 23,0 % som ble holdt enkeltvis i luftegårdene, mens de resterende ble holdt to eller flere sammen. 84,0 % av respondentene svarte at hesten gikk på beite hele døgnet en periode på sommeren. Undersøkelsen tyder på at hester av kaldblodstype tilbringer mye tid ute og oftest i gruppe, mens spranghester opplever størst restriksjoner på atferdsmessige behov, med minst beitebruk, kortest tid i luftegård og minst gruppehold.
Summary:
In spring 2014 a questionnaire was distributed by internet to Norwegian horse owners covering questions about housing, paddocks and grazing. A total of 2075 responded. 27.5 % had their horse in some kind of group housing system whereas 53.6 % had their horse in an insulated building and 16.5 % in an uninsulated building. The majority of the horses (53.1 %) kept in traditional stables, were kept in outdoor paddocks 5 – 10 hours per day and 35.0 % were kept in outdoor paddocks > 10 hours per day. During winter, 35.3 % of the horses kept in traditional stables were kept in paddocks < 300 m2. Among horses kept in traditional stables, 23.0 % were kept alone in the outdoor paddocks, while the rest kept the horses two or more together. 84.0 % of the respondents kept their horse on pasture all day for a period during summer. Horses of cold-blooded breed type were kept outdoors and in groups more often than warm-bloods. Especially show jumpers experienced more restrictions on natural behaviour by being kept for shorter time and more often single in the paddock, and least often on pasture.
... Several studies have shown that stallions can be kept in stable groups, with few injuries linked to aggressive interactions [18][19][20][21]. However, physical aggression rates are likely to be particularly high during group integration, when stallions are interacting for the first time and when the dominance hierarchy is being established [3,30,31]. Because agonistic encounters and rituals play a role in establishing dominance relationships within a group, we expect their rate and intensity to decrease with time, although not disappear completely, in a stable bachelor group [18][19][20][21]. ...
Horses are often kept in individual stables, rather than in outdoor groups, despite such housing system fulfilling many of their welfare needs, such as the access to social partners. Keeping domestic stallions in outdoor groups would mimic bachelor bands that are found in the wild. Unfortunately, the high level of aggression that unfamiliar stallions display when they first encounter each other discourages owners from keeping them in groups. However, this level of aggression is likely to be particularly important only during group integration, when the dominance hierarchy is being established, whereas relatively low aggression rates have been observed among stable feral bachelor bands. We investigated the possibility of housing breeding stallions owned by the Swiss National Stud in groups on a large pasture (5 stallions in 2009 and 8 stallions in 2010). We studied the pattern of agonistic, ritual and affiliative interactions after group integration (17-23 days), and the factors influencing these interactions (time after group integration, dominance rank, age or experience of group housing). We found that stallions displayed generally more ritual than agonistic and than affiliative interactions. The frequency of agonistic and ritual interactions decreased quickly within the first three to four days. The frequency of affiliative interactions increased slowly with time before decreasing after 9-14 days. A stable hierarchy could be measured after 2-3 months. The highest-ranking males had less ritual interactions than the lowest-ranking. Males had also less agonistic, ritual and affiliative interactions if they had already been housed in a group the previous year. Therefore, we found that breeding stallions could be housed together on a large pasture, because the frequency of agonistic interactions decreased quickly and remained at a minimal level from the fourth day following group integration. This housing system could potentially increase horse welfare and reduce labour associated with horse management.
The veterinary team frequently encounters foals as inpatients and during ambulatory duties, and thus play a key role in providing help and education to breeders. Having a good understanding of foal development from birth, weaning and beyond can have a significantly positive impact on the foal's future behaviour and quality of life. Equines behaving in a calm, safe manner is for the enjoyment of equestrian activities and is in the economic interests of those professionally involved. Successful management includes equipping the foal with a robust musculoskeletal system, healthy selective grazing behaviour, encouraging good social skills and safe behaviour around human handlers, all while promoting good quality of life for the young horse. This article is the first of two applying the research on foal behavioural development to good practice in the management and training of foals. This article covers the first 3 months of the foal's life, including socialisation and early handling and management of the foal, the second will cover the evidence surrounding weaning practices.
Every animal species has particular environmental requirements that are essential for its welfare, and when these so-called “basic needs” are not fulfilled, the animals suffer. The basic needs of horses have been claimed to be social contact, social companionship, free movement and access to roughage. To assess whether horses suffer when one or more of the four proposed basic needs are restricted, we examined several studies (n = 38) that reported behavioural and physiological reactions to these restrictions. We assigned the studies according to the four types of responses investigated: (a) Stress, (b) Active, (c) Passive, and (d) Abnormal Behaviour. Furthermore, the number of studies indicating that horses reacted to the restrictions were compared with the number of studies reporting no reaction. The limited number of studies available on single management restrictions did not allow conclusions to be drawn on the effect of each restriction separately, especially in the case of social companionship. However, when combinations of social contact, free movement and access to roughage were restricted, many of the horses had developed responses consistent with suffering. Passive Responses, indicating acute suffering, and Abnormal Behaviour, indicating suffering currently or at some time in the past, were especially clearly demonstrated. This provides further evidence of the usefulness of assessing behavioural parameters in combination with physiological measurements when evaluating horse welfare. This meta-analysis of the literature confirms that it is justified to claim that social contact, free movement and access to roughage are basic needs in horses.
In previous research, stall-housing growing horses resulted in decreased bone mineral content (BMC) of the third metacarpal (MCIII) compared to pasture-housing. To determine whether stall confinement negatively impacts bone, regardless of age, and whether the effects could be reversed upon return to pasture, 12 mature horses (5-15 years) and 12 yearlings were pair-matched by age and gender and randomly assigned to one of two treatment groups: pasture (PT) or stall (ST). Horses on PT remained there for the 84-d study, while horses on ST spent the first 28 d in stalls and the remaining 56 d on pasture. Radiographs and blood samples were taken on d 0 for baseline determinants. Radiographs and blood were taken every 7 d for radiographic photodensitometry estimates of BMC and analysis of osteocalcin (OC) and C-telopeptide (CTX-1)-markers of bone formation and degradation. There were no differences in BMC between treatments at the medial cortex of MCIII in mature horses. There were treatment (P=0.05) and day (P<0.01) differences in BMC at the lateral cortex of MCIII. In yearling horses, the BMC of the medial cortex of MCIII had a day difference with the lowest overall average at d 21 and highest at d 70 (P=0.04). There were day by treatment differences (P<0.05) for both OC and CTX-1 with the mature and yearling horses on ST having lower OC on d 14 than PT horses (P<0.05) indicative of reduced bone formation. In mature and yearling ST horses, CTX-1 was greater on d 14 and 28 compared to horses on PT (P≤0.05) suggesting greater bone resorption. Results from serum markers of bone formation and deformation confirm that stalling negatively impacts bone formation in horses regardless of age.
This article is an exploration of and experiment in animal‐centric ethnographic research. I first delve into key conceptual, scholarly, and practical issues which extend from the growing interdisciplinary interest in human‐animal relations, and the anthropological emphasis on multispecies ethnography. I then offer experimental ethnographic data focused on horses in show jumping stables in Canada. I approach the horses as both biological and sociocultural beings who affect and are affected by their formal jobs as show jumping horses. Through the concept of work‐lives, I also highlight the multi‐dimensional nature of their experiences as whole beings who have their own relationships and interests which are simultaneously shaped by and distinct from their human‐prescribed roles. I am interested in the methodological possibilities as gateways to deeper understanding of animals, more ethical practice within and beyond universities, and more just multispecies futures.
According to the joint University of Bristol and World Horse Welfare 2016 report, Horses in our Hands, many horse owners and professionals fail to recognise stress and pain behaviour in horses ( Horseman et al, 2016 ). This then leaves such issues to remain unresolved with the consequence of negative welfare. While the role of the veterinary team is quite clear when it comes to the identification, diagnosis and treatment of pain, there is clearly another, supporting role to play — that of helping horse people to prevent, recognise and resolve distress and chronic stress in equines.
This paper describes the development and pilot-testing of a horse welfare assessment protocol (HWAP). The HWAP consists of the collective measurement of numerous factors considered likely to affect a horse's welfare and is thereby designed to provide a holistic score of its welfare status and to identify potential risk factors. The draft protocol contains 47 measures: 15 animal-based, 24 resourcebased and eight management-based. It was tested in the autumn at two Swedish riding schools using a total of 37 horses of varying breed, gender and age. Each assessment was repeated after 16-25 days. The results showed that 66% (31/47) of the measures had over 85% repeatability between assessments. Results indicated occurrence of behavioural issues, eg aggression and avoidance, and potential risk factors, such as inadequate management routines and feeding regimes. Using the HWAP, the assessment of up to 22 horses could be carried out in one day. Changes were proposed to the draft protocol which included incorporating an ethogram to assess the human-animal relationship and assessing bit-related injuries. We propose that the protocol might: i) provide a firm basis for the welfare monitoring of horses; ii) identify important potential risk factors; iii) guide welfare improvement and management practices for horse owners and stable managers; and iv) contribute to the development of certification schemes for horse facilities.
The social environment plays an important role in modulating processes of the hormonal and behavioural profile of an animal in a variety of group-living species. In wild cavies for instance, unstable social environmental conditions during pregnancy and lactation lead to an infantilised biobehavioural profile of the male offspring. In the present study, the influence of the social environment during pregnancy and lactation on the male wild cavy offsprings’ plasma testosterone development, reproductive capacity and stress system activity was investigated. To this purpose, 12 sons whose mothers had lived in an unstable social environment during pregnancy and lactation were compared with 12 sons whose mothers had lived in a stable social environment during the same time. Plasma testosterone (T) and plasma cortisol (C) concentrations were determined from day 20 to 107 of age. Adrenal tyrosine hydroxylase (TH) activity and different parameters of reproductive capacity (weights of testes, epididymides and accessory sex glands, cellular composition of the testes, DNA fragmentation indices and sperm motility parameters) were analysed at day 107 of age. TH activity and plasma C were unaffected by different social environmental conditions early in life. The developmental time course of T concentrations, however, was significantly different: Sons whose mothers had lived in an unstable social environment during pregnancy and lactation showed a delayed increase in T concentrations around adolescence compared to controls. In contrast, no reproduction-related parameters measured within this study differed significantly between the two groups. Thus, early social instability affects plasma testosterone development during adolescence in a significant way but does not alter reproductive capacity or measures of stress later in life.
Although group housing of horses has become common practice, the risk of equine injury is substantial. The veterinary community is challenged to reduce this risk, particularly with regard to injuries caused by kicking and biting. Preventive measures should focus on the disposition of horses within the group, the introduction of new horses to the group and the design of the housing facility. Feeding methods as well as the structure of the environment should meet the physiological requirements for horses; there should be adequate space for exercise, extended foraging and the possibility of benign social interactions. Veterinarians need to educate horse owners and builders of equine facilities about the husbandry, feeding, use, behaviour and health of horses.
An ethogram of agonistic and related behaviors among equid bachelor band members was developed. Several key English-language studies on equids were reviewed to derive a preliminary inventory of specific behaviors to be included in the ethogram. A bachelor band of domestic pony stallions pastured together was observed for approximately 50 daylight hours to obtain detailed descriptions of each behavior, enable photographic and video documentation of behaviors, and identify any behaviors to be added to the preliminary inventory. An initial draft of the ethogram was sent to 65 equine researchers for review. Twenty-eight critical reviews were received and their suggestions considered for the final draft.A total of 49 elemental behaviors including five distinct vocalizations was included in the ethogram. Three complex behavioral sequences were also included. Most of the behaviors catalogued from the direct observation of pastured pony stallions were also found in the equid literature. For many, references to these behaviors specifically among males or bachelor band members were not found.The results offer a practical tool for quantitative research and other studies of equid inter-male behavior as well as for teaching of equid behavior, and should facilitate progress toward development of a complete ethogram for the horse and other equids.
Regrouping of cattle according to age, live weight or production stage is a common practice on farms. Our study aimed at determining how repeated regrouping modifies the social behaviour of dairy heifers, and more specifically if dominance relationships are formed more rapidly when animals become more familiar with regrouping. Thirty-two Holstein heifers were housed in pairs. From the age of 11 months, half of the heifers were placed in a new pen with a new penmate once or twice weekly for a total of 16 times over 11 weeks (regrouped heifers), while the other half remained in the same pen with the same penmate (controls). The heifers were monitored (a) for 3h immediately after the 2nd, 7th, 13th and 16th regrouping, (b) for 24h before the 1st regrouping, and after the 5th, 12th and 16th regrouping and (c) during a social confrontation test (with one animal for each treatment placed together in an arena) just before the 16th regrouping. Regrouping consistently induced agonistic interactions. Heifers exchanged the fewest agonistic interactions on the 7th regrouping and the greatest on the 16th. Dominance relationships were established most rapidly on the 7th regrouping (84±20min), but developed over the longest period on the 16th regrouping (158±56min). Observations for 24h after the 16th regrouping showed that regrouped heifers moved and changed their activity more often than the controls. No treatment differences were observed in the social confrontation test. In conclusion, heifers do not habituate to regrouping and repeated regroupings have little effect on their subsequent social behaviour. An optimum of around seven regroupings appear to produce the fewest agonistic interactions and allow dominance relationships to be established more rapidly.
In animal husbandry, pigs have to cope with social challenges when regrouped with unfamiliar conspecifics. Regrouping pigs may result in an acute stress and physical injuries thus reducing animal welfare. The aim of the present experiment was to evaluate the behavioural, cortisol and growth responses of pigs to a repeated social stress. Thirty-two growing-finishing pigs were housed in pairs. Animals of half of the pairs were placed in a new pen with a new partner three times a week during 4 weeks (R pigs, n = 8 pairs). Other animals stayed in the same pen with the same partner (C pigs, n = 8 pairs). During the first 90 min following each regrouping, vigorous fights were frequent in R pigs. Those pigs exhibited more agonistic behaviour than C pigs throughout the experiment (P < 0.05). The number of offensive acts realized by R pigs decreased throughout the experiment (P < 0.05) whereas the number of defensive acts did not vary (P > 0.1). The time-budget determined during 24 h 2 days after the third, sixth, ninth and 12th regrouping was similar in R and C pigs except the percentage of standing that was higher in R pigs after the last regrouping. R pigs tended to have a lower daily liveweight gain at the fifth regrouping (P = 0.07). Salivary cortisol concentrations were higher in R than in C pigs 4–5 h after the second and fifth regrouping (P < 0.05) but were similar in both groups after the ninth and 11th regrouping. Basal cortisol measured 2 days after the last regrouping in plasma and saliva was higher in R than C pigs. In response to a dexamethasone/ACTH challenge, cortisol in saliva and plasma was similar in both groups (P > 0.05). The behavioural and cortisol responses to regrouping and relocation in pigs decreased over time but were still obvious after 12 mixings. Repeated regroupings induce a chronic stress in pigs without altering severely growth rate.
The risk of injuries is of major concern when keeping horses in groups and there is a need for a system to record external injuries in a standardised and simple way. The objective of this study, therefore, was to develop and validate a system for injury recording in horses and to test its reliability and feasibility under field conditions.
Injuries were classified into five categories according to severity. The scoring system was tested for intra- and inter-observer agreement as well as agreement with a 'golden standard' (diagnosis established by a veterinarian). The scoring was done by 43 agricultural students who classified 40 photographs presented to them twice in a random order, 10 days apart. Attribute agreement analysis was performed using Kendall's coefficient of concordance (Kendall's W), Kendall's correlation coefficient (Kendall's τ) and Fleiss' kappa. The system was also tested on a sample of 100 horses kept in groups where injury location was recorded as well.
Intra-observer agreement showed Kendall's W ranging from 0.94 to 0.99 and 86% of observers had kappa values above 0.66 (substantial agreement). Inter-observer agreement had an overall Kendall's W of 0.91 and the mean kappa value was 0.59 (moderate). Agreement for all observers versus the 'golden standard' had Kendall's τ of 0.88 and the mean kappa value was 0.66 (substantial). The system was easy to use for trained persons under field conditions. Injuries of the more serious categories were not found in the field trial.
The proposed injury scoring system is easy to learn and use also for people without a veterinary education, it shows high reliability, and it is clinically useful. The injury scoring system could be a valuable tool in future clinical and epidemiological studies.
Adults play an important role in regulating the social behaviour of young individuals. However, a few pioneer studies suggest that, more than the mere presence of adults, their proportions in social groups affect the social development of young. Here, we hypothesized that aggression rates and social cohesion were correlated to adult-young ratios. Our biological model was naturally-formed groups of Przewalski horses, Equus f. przewalskii, varying in composition.
We investigated the social interactions and spatial relationships of 12 one- and two-year-old Przewalski horses belonging to five families with adult-young ratios (AYR) ranging from 0.67 to 1.33. We found striking variations of aggression rates and spatial relationships related to the adult-young ratio: the lower this ratio, the more the young were aggressive, the more young and adults segregated and the tighter the young bonded to other young.
This is the first study demonstrating a correlation between adult-young ratios and aggression rates and social cohesion of young individuals in a naturalistic setting. The increase of aggression and the emergence of social segregation in groups with lower proportions of adults could reflect a related decrease of the influence of adults as regulators of the behaviour of young. This social regulation has both theoretical and practical implications for understanding the modalities of the influence of adults during ontogeny and for recommending optimal settings, as for instance, for schooling or animal group management.
Plasma cortisol is largely bound to corticosteroid-binding globulin (CBG), which regulates its bioavailability by restricting exit from capillaries. Levels of CBG may be altered by several factors including stress and this can influence the amount of cortisol reaching cells. This study investigated the effect of social instability on plasma concentrations of CBG, total and free (not protein bound) cortisol in horses. Horses new to our research herd ('newcomers') were confined in a small yard with four dominant resident horses for 3-4 h daily for 3-4 (n = 5) or 9-14 (n = 3) days. Jugular blood was collected in the mornings from newcomers before the period of stress began ('pre-stress'), and then before each day's stress. Residents were bled before stress on the first and thirteenth day. Residents always behaved aggressively towards newcomers. By the end of the stress period, all newcomers were subordinate to residents. In newcomers (n = 8) after 3-4 days of social stress, CBG binding capacity had fallen (P = 0.0025), while free cortisol concentrations had risen (P = 0.0016) from pre-stress values. In contrast, total cortisol did not change. In residents, CBG had decreased slightly but significantly (P = 0.0162) after 12 days of stress. Residents and newcomers did not differ in pre-stress CBG binding capacity, total or free cortisol concentrations. However, by the second week of stress, CBG binding capacity was lower (P = 0.015) and free cortisol higher (P = 0.030) in newcomers (n = 3) than in residents. Total cortisol did not differ between the groups. In conclusion social stress clearly affected the adrenal axis of subordinate newcomer horses, lowering the binding capacity of CBG and raising free cortisol concentrations. However, no effect of stress could be detected when only total cortisol was measured. Therefore, to assess adrenal axis status accurately in horses, it is essential to monitor the binding capacity of CBG and free cortisol concentrations in addition to total cortisol levels.
Because of welfare concerns and increased labor efficiency, calves are increasingly housed in groups. To reduce variability in live weight within groups, farmers frequently regroup calves according to growth rate. We assessed the consequences of repeated regrouping and relocation on the welfare of 32 male Holstein calves housed in pairs. Animals of half of the pairs (regrouped calves) were placed in a new pen with a new partner once a week for 14 wk. Animals of the other half of the pairs (control calves) stayed in the same pen with the same partner. Behavior was observed for the 3 h following four mixings and for 24 h after all relocations were finished. The functioning of the hypothalamic-pituitary-adrenal axis and of the sympathetic nervous system were assessed. Calves were weighed once a week, their health was assessed daily, and abomasa were inspected when the calves were slaughtered. Calves reacted to the first mixing by interacting with the new partner and increasing their general activity (sniffing the partner in regrouped calves vs controls: 5.5 vs 2.9, P < 0.01; percentage time stepping: 3.2 vs 1.3, P < 0.001). This effect disappeared by the ninth mixing. After all relocations were completed, regrouped calves were more active at the end of the day and less active at night (P < 0.05). Cortisol responses to exogenous ACTH were higher in regrouped calves (integrated response: 6,688 vs 5,508 ng x min/mL, P < 0.01). Basal cortisol levels, ACTH responses to corticotropin-releasing hormone, activities of catecholamine-synthesizing enzymes (tyrosine hydroxylase and phenylethanolamine N-methyl transferase), and the incidence of health problems and growth rates did not differ between the two groups. Regrouped calves had fewer abomasal ulcers. Apart from the increased sensitivity of the adrenal cortex of regrouped calves to ACTH and the modification in the daily rhythm of activity, there was no clear evidence that repeated regrouping and relocation stresses calves. Aggression between calves was rare, and calves seemed to habituate to repeated mixing.
Control of feral horse populations (Equus caballus) on public lands is restricted to nonlethal methods. These methods can limit population growth; however, efficacy may vary among populations with differing demography and social structures. Characteristics of many western feral horse populations are well documented, but fewer data are available for Atlantic barrier island populations. Therefore, we monitored a population of feral horses on Cumberland Island, Georgia from 1986 to 1990. Population growth averaged 4.3% annually with a stable age structure. Mean size of bands with ≥1 stallion was 4.6 horses. The adult sex ratio for the population was 0.6 females:1.0 males. About 66% of mares foaled during a given year and no juvenile females foaled. Annual survival rates averaged 61.1% for female foals, 58.8% for male foals, and 92.4% for mares. Most bands contained a dominant or codominant stallion, mares and-or juvenile females, and foals. Most mares (62.5%) changed bands ≥1 time during our study. Bachelors represented 50.4% of stallions. These population characteristics differed from other feral horse populations. The small band size, large number of bachelors, high degree of band instability, and codominance of band stallions on Cumberland Island likely will limit the efficacy of some forms of nonlethal population control.
With the goal of characterizing the type and degree of injuries and blemishes incurred by horses living under natural social conditions, all members of a semi-feral herd of ponies were inspected on 4 occasions over a period of 28 months. Two occasions were during breeding/foaling season and 2 during non–breeding/foaling season months. On each occasion, each animal was examined (N = 47-65) and all injuries or blemish marks were recorded. Based on the types and number of injuries or blemishes, an injury/blemish grade was assigned for each inspection, ranging from 1 for no blemishes to 6 for more than 1 open wound. Almost all injuries and blemishes recorded were extremely mild. Only 12 of the 213 inspections and 14 of the 858 total injuries and blemishes involved wounds affecting tissues other than hair and skin.Males had significantly greater mean injury/blemish grade than females (P < .0001). For all social categories and ages, the mean injury/blemish grade was significantly greater in the breeding/foaling season months than during the non–breeding/foaling season (P < .0001).All foals were blemish-free at the non–breeding/foaling season inspections (n = 24) and relatively blemish-free (9 of 14) at the breeding/foaling season inspections. The rump and the barrel areas were the most common site of injuries or blemishes, both as a percentage of the total injury count and as a percentage of inspections involving those areas. These findings are consistent with the seasonal and gender patterns of aggressive behavior seen in this herd. Compared with reports of truly feral horse populations, it appears that injuries are fewer and less severe in this semi-feral herd. In addition, there appear to be fewer leg injuries in this semi-feral herd than has been described for truly feral horse populations.
Horses kept in stalls are deprived of opportunities for social interactions, and the performance of natural behaviors is limited. Inadequate environmental conditions may compromise behavioral development. Initial training is a complex process and it is likely that the responses of horses may be affected by housing conditions. Sixteen 2-year-old Arabian horses were kept on pasture (P) (n=8) or in individual stalls (S) (n=8). Twelve horses (six P and six S) were subjected to a standardized training procedure, carried out by two trainers in a round pen, and 4 horses (two P and two S) were introduced to the round pen but were not trained (C; control). On sample collection day 0, 7, 21 and 28, behavior observations were carried out, blood samples were drawn and heart rates were monitored. Total training time for the stalled horses was significantly higher than total time for the pastured horses (S: 26.4±1.5 min; P: 19.7±1.1; P=0.032). The stalled group required more time to habituate to the activities occurring from the start of training to mounting (S: 11.4±0.96; P: 7.3±0.75 min; P=0.007). Frequency of unwanted behavior was higher in the stalled horses (S: 8.0±2.0; P: 2.2±1.0; P=0.020). Pastured horses tended to have higher basal heart rates on day 0 (S: 74.7±4.8; P: 81.8±5.3 bpm; P=0.0771). While the physiological data failed to identify differences between housing groups, the behavioral data suggest that pasture-kept horses adapt more easily to training than stalled horses.
Group housing of horses is not widely applied in practice despite the welfare advantages of keeping animals socially rather than individually. In particular, concerns have been raised about the possible increased risk of injury and how to introduce a new horse into an established group.This study investigated two hypotheses: (1) pre-exposure of young horses in neighbouring boxes reduces the frequency of aggressive interactions when the same horses are subsequently put together in a paddock compared to horses without this previous box experience, (2) the occurrence of aggressive behaviour, in particular contact aggression in the paddock can be predicted after observing the horses’ social interactions in neighbouring boxes.Danish Warmblood mares (n=20), 2 years old, were kept in two groups of 10 horses. In total, 60 encounters were arranged whereby each horse was confronted pair-wise with six horses from the other group, three according to each treatment: treatment I—box (B) and subsequent paddock meeting (BP), and treatment II—only paddock meeting (P). Horses met in neighbouring boxes for 5min and together in the same paddock for 10min. The frequencies of aggressive and non-aggressive interactions were analysed from video recordings.Total aggression levels between BP and P did not differ, but ‘contact aggression’, i.e. bite, kick, strike, push, tended to be lower in BP compared to P (median BP=1, P=2; p=0.083) and there were less bites in BP than P (median BP=0, P=1; p=0.050). Frequencies of ‘non-aggressive’ interactions, e.g. friendly approach, nasal sniff, were lower in BP than P (median BP=2.5, P=10; p
In an experiment on the effects of social environment and training on the human-animal relationship, 20 horses were handled according to a defined schedule. Eight horses were housed singly and 12 horses were housed in four groups of 3 horses. Horses were handled three times per week in 10 min sessions from an age of 6 months until 2 years of age during two winter periods. A total of 50 and 70 sessions were given in the first and second period, respectively. Five randomly allocated people performed the training. The training scheme involved leading, tying up, touching, lifting feet, etc. in 43 stages. The horse had to fulfil the performance criteria of each stage in order to get to the next stage. In the first winter period, horses were led to the stable when they had "passed" a stage or after 10 min of training. In the second winter period, horses would start off at stage 1 again, and when they "passed" a stage they went on to the next stage within the same training session. Because of the change in training procedure results were analysed separately for the two winter periods. There was a significant difference between trainers in the number of times they allowed a horse to "pass" a stage within each winter period (χ32, P<0.05; χ32, P<0.001 for the first and the second winter period, respectively). Group housed horses "passed" more stages than single housed horses (17 versus 14; 27 versus 18 in the first and second winter period, respectively; P<0.05 for the interaction). Singly housed horses bit the trainer more frequently than did group housed horses (P<0.01). The responses of group housed horses to training clearly demonstrate the benefits of raising young horses in groups.
The aim of this study was to investigate social behaviour in differently reared stallions in their respective environments; one group of stallions was reared under typical domestic conditions whereas the other group was reared and lives under natural conditions. The domestic group consisted of 19, 2-year-old stallions (Equus caballus), which were all weaned at 4 months of age and experienced either individual or group housing facilities before being pastured with the other similarly aged stallions. The natural living and mixed age group of Przewalski stallions (E. przewalskii) consisted of 13 stallions, most of which were juveniles (n=11, ≤4 years; n=2, >9 years). The domestic group was studied in a 4-ha enclosure at the Danish Institute of Agricultural Sciences and the Przewalski group under free-ranging conditions in a 75-ha enclosure in the Askania Nova Biosphere Reserve, Ukraine. Behavioural data was collected during 168h of direct observation. The occurrence of 14 types of social interactions was recorded and group spacing behaviour was studied using nearest neighbour recordings. In spite of very different environments, reflecting domestic and natural rearing conditions, many similarities in behaviour was found. Play and play fight behaviour was very similar in the two stallion groups. Quantitative differences were found in social grooming since Przewalski stallions groomed more frequently (P=0.004), and in investigative behaviours, since domestic stallions showed more nasal (P=0.005) and body sniffing (P
Domestic horses (Equus caballus) are typically kept in individual housing systems, in which they are deprived of physical contact. In order to study the effects of social restrictions on behaviour in young horses, nineteen 2-year-old stallions were housed either singly (n=7), or in groups of three (n=12) for 9 months. Subsequently, the stallions were released into two separate 2ha enclosures according to treatment, and recordings were made on social interactions and nearest neighbours during a 6-week-period, 28h per week. Previously group stabled stallions frequently had a former group mate as their nearest neighbour (P=0.001), whereas previously singly stabled stallions did not associate more with their former box neighbours, to whom physical contact was limited by bars during the previous treatment. The nearest neighbour was more frequently recorded to be within one horselength of singly stabled than of group stabled stallions (P=0.005). More aggressive behaviour was recorded in the group of previously singly stabled stallions, i.e. bite threats (P=0.032), whereas group stabled stallions tended to make more use of subtle agonistic interactions (displacements, submissive behaviour). Singly stabled stallions also responded to the 9 months of social deprivation by significantly increasing the level of social grooming (P
The validity of antibody and lymphocyte response as measures of social stress in farmed red deer hinds was assessed by comparison with other indices of stress. Ten ‘wild’ red deer (mixed, M), born to wild hinds post-capture, were each housed in separate groups of five farmed deer. After 2 weeks the groups were completely re-mixed. Mixing was repeated at weekly intervals for 4 successive weeks. As a control, ten ‘wild’ deer (C) were maintained in the same two groups of five throughout the study. All wild deer were immunised with keyhole limpet haemocyanin (KLH) 1 week prior to remixing (week 2). Mixed deer were subjected to more aggression than C deer (P < 0.001). At week 6, plasma cortisol concentrations after ACTH injection increased more in M than C deer (P < 0.05). Lymphocyte responses to KLH were significantly lower in M than C deer (P < 0.05), but there were no differences in antibody response to KLH. It is concluded that the repeated mixing of groups was a significant social stressor and that lymphocyte response to an antigen may be a more sensitive immunological measure of social stress in red deer than antibody response.
The main objective of this experiment was to study the development of social hierarchy and the underlying frequencies of physical and non-physical agonistic interactions in a herd of dairy cows. Thirty-two lactating Holstein cows were randomly allocated to form two groups of 16 animals each (Groups A and B). Each group was kept in a separate free stall pen for 5 weeks. Eight randomly selected cows from each original group were then combined to form a new group (Group C). Behavioral observations of agonistic interactions were carried out for 2-h periods, beginning just after grouping and continuing at 48-h intervals until Day 18. For Groups A and B, additional behavioural observations were made on Days 25 and 32. Agonistic interactions were classified as physical (bunting, pushing and fighting) or non-physical (threatening and avoiding). With all three groups, the total number of interactions was greatest immediately after grouping (228, 329 and 305 events per observation period). Interactions then decreased, ranging from 45 to 189. The occurrence of physical and non-physical agonistic behavior changed over time in all three groups. In Groups A and B, between 55 and 64% of encounters were physical, and between 36 and 45% were non-physical for 48 h after grouping. Physical encounters then decreased to 40.2±3.8% and 38.7±6.8%, and non-physical increased to 60.5±4.5% and 61.2±6.7% in Groups A and B, respectively. In Group C, the point at which the proportion of physical to non-physical agonistic behavior reversed occurred sooner. Just after grouping, physical encounters in Group C occurred 61.1% of the time and non-physical 39.0%. Beginning on Day 2, they occurred 40.5±6.5% and 59.4±6.5%, of the time, respectively.
With the aim of testing the hypothesis that regrouping decreases milk production in French Alpine goats that were lactating, a study was done using two groups (n=8, 7). During their third month after parturition, four goats from each group were exchanged (first regrouping) between pens and left for 2 weeks, then the same two subgroups of four goats were taken back to their original pen for another 2 weeks (second regrouping). In the third regrouping, the two groups were all placed in the one pen. Milk production and social behaviour were measured daily before and after each regrouping. All regroupings led to an increase in aggressive behaviours that last by 1–2 days. Mean daily milk production decreased after first (2.82±0.2kg versus 2.53±0.2kg; P
The space allowance appropriate for sows in group housing remains scientifically undefined, since the social space requirement of a group of animals and the factors which affect this are unknown. Eight established groups of six pregnant, multiparous sows were used in a replicated Latin Square design of experiment, with 7 day periods, to compare four pen sizes providing 2.0, 2.4, 3.6 or 4.8 m2/sow. For the last 48 h of each 7 day period, a continuous video recording was made to determine general behaviour and all social interactions. Time spent rooting increased progressively with increasing space allowance, whereas time spent sitting and standing inactive were both progressively reduced. The total frequency of social interactions and aggressive behaviour both increased with decreasing space allowance. The Attack:Retreat ratio was significantly higher, and the Avoidance Index significantly lower, in the smallest pen. All body regions had the highest count of lesions after sows had been in the smallest pen, with damage levels being reduced as pen area increased. Analysis of body lesion scores, combining incidence and severity, gave the same treatment effects. In conclusion, the results indicated that a minimum space of between 2.4 and 3.6 m2/sow was necessary in the conditions of this experiment to promote good welfare. This result cannot be generalised to situations of different group size, group stability or feeding method.
This study was undertaken to describe the effect of previous acquaintance on aggressive behaviour in repeatedly regrouped pigs and the nature of interaction between sexes. Four replicates of each 100 pigs (half entire males, half females) were weaned at 4 weeks and kept litterwise until 8 weeks, when they were randomly allocated to 10 pens of 10 pigs each. Random regrouping took place 4 times at 4 week intervals. In weeks 2–4 of each mix-period, aggressive behaviour was repeatedly recorded during feed competition. The dependent variables frequency and intensity of aggression were analysed (GLM-anova) in relation to class variables defined by combinations of acquaintanceship in litters and mix-periods. Additional class variables tested were intra and intersexual pairwise interactions (sex–classes). In mix-period 1 the frequency of aggression was significantly lower between littermates than between non-littermates (1.04±0.7 vs. 1.20±0.2, P=0.03), just as the intensity tended to be lower (P=0.07). In mix-period 2 there was no longer any difference between littermates, nor any difference between pigs that had been together in the immediately preceding mix-period and those that had not. In mix-period 4 there was a tendency for pigs that had been together also in the preceding period to interact with higher intensity than those that had not been together. Intrasexual interactions between males and females did not differ, but the frequency of male-initiated intersexual interactions was significantly higher than female-initiated ones (P=0.0001). No differences were found in intensity. The frequency of aggression declined over mix-periods (P=0.005) which could be due to habituation or age, whereas the intensity increased (P=0.0001), mainly due to female aggression towards males. The results of this study indicate that frequent regrouping seems to be a situation to which the social behaviour of the pig is not well adapted, and that the mechanisms whereby pigs recognise, assess and become familiar with strangers are disturbed. The found sex differences may, however, relate to the pigs' developmental stage.
Many horse owners tend to group horses according to gender, in an attempt to reduce aggressive interactions and the risk of injuries. The aim of our experiment was to test the effects of such gender separation on injuries, social interactions and individual distance in domestic horses. A total of 66 horses were recruited from 4 different farms in Norway and Denmark and divided into six batches. Within each batch, horses were allotted into one mare group, one gelding group and one mixed gender group, with most groups consisting of three or four animals. After 4-6 weeks of acclimatisation, a trained observer recorded all social interactions using direct, continuous observation 1 h in the morning and I h in the afternoon for three consecutive days. Recordings of the nearest neighbour of each horse were performed using instantaneous sampling every 10 min. The horses were inspected for injuries before grouping, day I after grouping and after 4-6 weeks. No significant effect of gender composition was found on social interactions (P > 0.05), spacing (P > 0.07) or injuries (P > 0.23). Eighty percent of all aggressive interactions recorded were threats, not involving physical contact. Horses with the smallest space allowance showed the highest mean number of aggressive interactions (28.6 +/- 6.1 interactions per 6 h) compared to the mean of all the other batches (8.3 +/- 1.0 interactions per 6 h). Very few injuries were found and most were superficial. In conclusion, gender composition does not seem to have any effect on aggression level, spacing or injuries. However, the early social experience of horses, management of feeding and space allowance probably represents more important factors for successful group housing of domestic horses.
To investigate the effect of repeated regrouping and relocation (R&R) on behaviour of steers, 72 Holstein–Friesian (14-month-old; 441 AE 3.2 kg) steers were assigned to either control (n = 30; C) or regrouped (n = 42; R) treatments and housed six per pen in 12 pens. The R steers were exposed to six R&R over 84 days. New pen cohorts were allowed to stabilise for 14 days and none of the R steers were allowed to share the same pen or pen mates, where or with whom, they were previously housed. Control steers were housed in the same pen with the same pen mates. Each steer was marked on its back with an individual identification code. Twelve cameras were used to observe and record behaviour for each pen allowing observation of all individual steers continuously for a week following each R&R. The following behaviours were recorded for each steer: lying, standing, eating, drinking, head-to-head contact with another animal while not eating, head contact with the body of another animal and bodily contact with none, one, two or three steers. Behaviour was observed by instantaneous scan sampling after each R&R, at 2 min intervals for 2 h on day 1; at further 20 min intervals on days 1 and 2; and at 120 min intervals from day 3 to 7. Where appropriate, the % of time spent in each behaviour was calculated from the data on total counts in each behavioural category. The total count data were analysed by x 2 -statistics for all behavioural categories. Steers were weighed before each R&R. Average daily gain from day 0 to 84 was analysed by ANOVA. During the first 2 h observation period following mixing, R steers displayed a greater (P < 0.05) % of time standing (following the first to sixth R&R), eating (first to fourth and sixth R&R) and drinking (first, third and fourth R&R) than control steers. In the 20 min observational period, a greater % (P < 0.05) of time was
Effects of rearing condition on behavioural and physiological reaction to social confrontations and to social and non-social stressors were studied in female pigs. The pigs were reared under either poor (the standard farrowing crate) or enriched (group of free-ranging sows with piglets) conditions. At the age of 14-17 weeks, the pigs were exposed to a series of social confrontations where an intruder was introduced into the home pen of a resident. The results show the presence of a clear difference in terms of aggressive behaviour between residents and intruders from enriched but not from poor rearing conditions. Furthermore pigs reared under poor conditions inflicted more wounds on each other. We suggest that this reflects a difficulty in establishing a dominance relationship in poorly reared pigs, caused by impaired development of social skills in these pigs. Subsequently, reaction to novel object, non-social and social stress was measured in adult age, showing that the effects of rearing conditions are long-lasting, and give rise to differences in reaction to challenges in that pigs from enriched rearing conditions showed more avoidance behaviour than pigs from poor rearing conditions.
The aim of this thesis was to investigate whether specific anecdotal concerns related to keeping horses in groups are supported by science and, if so, provide scientifically based recommendations that could be implemented in practice. The aim of studies I and II was to identify methods for mixing unfamiliar horses that could minimise aggressive interactions and associated risk of injury. Results of study I revealed that pre-exposure of young horses in neighbouring boxes tended to lower contact-aggression (e.g. kicks, strikes) and biting behaviour in particular was reduced when the same pair of horses subsequently met in a paddock. This was not found when older horses were mixed (study II). Aggressive behaviour received by a new horse was not significantly different in meetings when it met one other horse compared to meeting two unfamiliar horses at the same time. Removing a horse from a group of four in study III was generally unproblematic. Most horses approached the handler when she was catching the horse and while standing with it in the middle of the paddock. Thus, potential risk may be higher in situations when the handler remains relatively stationary, as other horses of the group have time to approach. Rank did not influence the number of horses following to the paddock gate and interactions between horses were rare. Since horses naïve to social separation may be more difficult to handle away from the group, the objective in study IV was to investigate whether the initial presence of a companion horse would modify responses to separation. Results revealed no significant differences in heart rates and the number of training sessions required when the horses were subsequently trained in the absence of the partner compared to horses trained alone from the start. In summary, results give little support for the original areas of concerns about mixing and separating horses. Risk of injury to both horses and humans should not be overestimated when handling horses in groups, but being aware of potential risk situations and being able to react accordingly is likely to increase horse welfare and human safety.
The aim of the present study was to study the effects of social instability (regrouping) during the second trimester (7 weeks) of pregnancy on aggression, cortisol concentrations and growth in goats and its consequences for survival, growth and some aspects of behavioural development in the kids. Six weeks after mating, 32 goats were distributed into eight groups. In four of the groups, randomly chosen pairs of goats were rotated between groups every Monday morning (around 08:30h) for 7 weeks (unstable groups), starting 6 weeks into gestation (second trimester). The remaining four groups were kept stable throughout the entire pregnancy (stable groups). The adult goats were video recorded for 6h twice a week for the first, second, fourth and seventh regrouping and for the 2 last weeks before expected birth. Blood samples of the adult goats were collected in a period from 1 week before the start of the first regrouping and until 1 week before expected birth. Blood samples from a maximum of two kids from each litter were collected at 3 weeks of age. Two kids from each litter were subjected to two types of behavioural tests: a 'social test' at the age of 1 and 7 weeks and a 'novel object test' at the age of 5 weeks. Except for the higher aggression level in the unstable groups, social instability did not have any other significant effects on factors such as growth, cortisol level or kid production in the goats. There were only minor effects on the behavioural development in the goat kids. However, kids from the unstable groups showed more escape attempts in the first trial of a 'social test', spent more time in contact with a novel object and unfamiliar kids, and showed less fear (escape attempts) after they were given one exposure to the social test situation. Furthermore, kids from unstable groups had a lower basal cortisol level than kids from stable groups.
Former experiments have shown that social experience during nursing in either a group housing system with straw or a very spacious farrowing/nursing pen with straw, increases social skills of growing pigs considerably. Based on experiences in Taiwan, it was postulated that such skills could also be acquired in the period between being taken from flatdecks at 10 weeks of age and the age of 5 months. In an ‘arena’, copied from the one used for introducing new pigs (gilts) in a group housing system, agonistic behaviour and number and severity of lesions of the integument of 384 experimental GY x DUROC hybrid gilts were studied and compared with data of an equal number of control gilts in three different treatments (repeated once). The experimental animals were born in individual farrowing crates with slatted floors. They were weaned at 30 days and kept in flatdeck cages with two other litters, until 10 weeks. At that time they were kept in groups of eight on fully slatted floors and treated with regrouping and repenning several times until the final testing at an age of 5 months. In sequential experiments, this treatment was given twice, three times or four times and effects on social (agonistic) behaviour were studied. The control animals were born in a group farrowing house with straw, where they stayed 30 days (some days after weaning). As for the experimental pigs, two litters were grouped in flatdeck cages. At 10 weeks of age they were moved to pens with fully slatted floors, where they remained in groups of eight undisturbed until final testing at 5 months. At an age of five months, eight unfamiliar experimental animals were grouped in a so-called arena for 24 h. So were 8 control pigs in the same week. Time-lapse video observations during these 24 h (2 frames/s) revealed that the pigs were fighting for social dominance during this period. Experimental pigs that had been regrouped four times only showed 57% of bilateral agonistic actions and 82% of total fighting time, in comparison with control pigs. Three times regrouping still showed a statistically significant lower amount of fighting, but twice regrouping did not. After 24 h in the arena, the number of lesions of the integument was significantly smaller in groups that had experienced regrouping 3 or 4 times. These results proved that social experience by regrouping and repenning prepared gilts for agonistic encounters, by improving their social skills.
Twenty-three (9 male, 14 female) wild horses (Equus caballus) in the Great Basin Desert were immobilized by ground techniques with succinylcholine chloride during 1,950 person-hr. Induction (means = 2.09 +/- 0.59 min) and recovery (means = 12.4 +/- 5.0 min) were rapid and most animals were returned in less than 10 min to original bands. Dosages ranged from 0.66-0.77 mg/kg body weight and neither abortions nor band changes in group membership resulted. However, a few concerted efforts up to 24 hr were needed to return some animals to original bands and three non-drug related mortalities occurred. The responses of bands to darted members and the overall influence of the operation on reproduction, movements, and social structure are presented.
The experiment involved 40 mid-lactating Comisana ewes. The animals were housed in straw-bedded pens and assigned to a control group (n = 10) and two test groups of 15 subjects each. Control ewes were never moved from their pen and peers throughout the experiment period, whereas test animals were subjected to either regrouping (RG) or regrouping and relocation (RGRL) three times at weekly intervals (d 7, 14, and 21 of the trial). Three behavioral recordings were conducted after each social and pen exchange over a 6-h period (1000 to 1600). Animals from groups RG and RGRL were bled immediately before each regrouping and relocation and 15 and 60 min afterward. The phytohemagglutinin skin test was performed at d 9, 16, and 23. Milk yield was recorded when the ewes were mixed and moved, and before and after each mixing and moving procedure. Individual milk samples were analyzed for composition, renneting parameters, and bacteriological characteristics; samples with more than 10(6) somatic cells/mL were cultured for mastitis-related pathogens. Control ewes spent more time lying than groups RG (P < 0.001) and RGRL (P < 0.01) and less time in ambulatory activities than RGRL sheep (P < 0.05). Moved and remaining ewes showed a higher number of aggressive interactions than control subjects (P < 0.001 and P < 0.01, respectively). Control sheep showed the highest cell-mediated immune response compared with both moved and mixed ewes (P < 0.001 and P < 0.01, respectively). The RGRL ewes gave lower yields of milk than did the control ewes on the days after the first (P < 0.05) and the second (P < 0.01) change of pen and peers. The RGRL ewes also had a lower fat content (P < 0.05) than control ewes in the milk yielded on the day of the first regrouping and relocation and a lower milk protein content (P < 0.05) on the following day. The RG treatment resulted in the ewes yielding milk with a lower fat content (P < 0.01) on the day of each mixing procedure as compared with controls and in a decreased milk protein content on the days after the first (P < 0.05) and the second regrouping (P < 0.01). One case of subclinical mastitis was recorded in both the RG and RGRL groups, whereas no cases were detected in control group. These findings suggest that regrouping and relocation may cause increased aggression, altered immune responses, and short-term effects on the production performance of lactating ewes. These practices should be performed by attempting to minimize their impact on animal welfare.
Studies on the prevalence and predisposing factors of bite and kick injuries in horses have not been reported in a population-based data sample.
To investigate the prevalence of bite and kick injuries in horses and associated risk factors in a representative sample of horses in Switzerland.
A questionnaire on the incidence of disease and injury, which included the frequency of bite and kick injuries and their association with breed, housing, use and feeding regime, was sent to 2559 horse owners randomly selected throughout Switzerland.
The data of 2912 horses with 897 disorders diagnosed by a veterinarian were analysed. There were 231 injuries, 50 (21.6%) caused by a bite or kick from another horse; this number corresponded to 5.6% of all diseases and injuries and concerned only 1.7% of all the horses evaluated. Warmblood, Thoroughbred and Arabian horses had a 4.3 times higher risk of bite or kick injuries than horses of other breeds. Eighteen per cent of injuries were associated with a change in housing management and occurred regardless of whether horses were kept in groups permanently or sporadically.
A stable group hierarchy and a housing system that provides adequate space and is adapted to horse-specific behaviour are important factors in prevention and kick and bite injuries.
We investigated the effects of the introduction of foreign adults on the behavior of young horses. First, we observed the behavior of 1- and 2-year-old domestic horses housed in same-age and same-sex groups (a standard housing system, but different from a natural situation). Then, two same-sex adults were introduced into each experimental group. Observations made before, during and after an introduction indicated that young horses reared in homogeneous groups of young had different behaviors compared to other domestic horses reared under more socially natural conditions. After the introduction of adults, young horses expressed new behaviors, preferential social associations emerged, positive social behavior increased and agonistic interactions decreased. These results have important implications both for understanding the influence that adults may have on the behavior of young horses, and in terms of husbandry, indicating the importance of keeping young horses with adults, although further studies are still necessary.
The Domestic Horse: The Evolution, Development and Management of Its Behaviour
- L Boyd
- R Keiper
Boyd, L., Keiper, R., 2005. Behavioural ecology of feral horses. In: Mills,
D., McDonnell, S. (Eds.), The Domestic Horse: The Evolution, Development and Management of Its Behaviour. Cambridge University Press,
UK, pp. 55-82.
A Dictionary of Ethology
- K Immelmann
- C Beer
Immelmann, K., Beer, C., 1992. A Dictionary of Ethology. Harvard University Press, London, England.
Horse Behavior, second ed
- G H Waring
Waring, G.H., 2003. Horse Behavior, second ed. William Andrew Publishing, New York, USA.
The Domestic Horse: The Evolution, Development and Management of its Behaviour
- C Feh
Feh, C., 2005. Relationships and communication in socially natural horse
herds. In: Mills, D., McDonnell, S. (Eds.), The Domestic Horse: The Evolution, Development and Management of its Behaviour. Cambridge
University Press, UK, pp. 83-93.
Behavioural ecology of feral horses
- Boyd