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Hausberger, M. (2008). Temperament and Personality in Horses: An Overwiev. In IESM 2008.
Abstract: The existence of individual variations in behaviour has been demonstrated in all species investigated. Horses do show individual variations in a variety of behaviours from an early age on, as well as in behavioural traits underlying temperament/personality. Temperament is generally described as the “biological” (i.e.genetic) basis on which personality, as a result of environmental influences (i.e. experience), will be constructed. Indeed, genetic factors such as breed or patriline do have an influence on aspects like emotional reactions to fear-inducing situations or cognitive abilities while environmental factors, such as the conditions of life or the type of work performed, have also an influence on horse personality. We will review here the existing evidence of this interplay between genetic and environmental influences, showing that different traits can be differently influenced, and then look more thoroughly at the processes involved.
A particular accent will be given to the influence of the human-horse relation on personality traits of horses, both at adult stages through management, daily interactions and type of work, and at early stages through management and handling of foals. The question of the stability of traits across situations and over time, that is of the possible predictibility of behavioural traits, is central, especially where the transfer from experimental situations (behavioural tests) to working situations and performance is concerned. The question of methodological approaches (behavioural tests, observations, questionnaires) can be crucial here and will be discussed. In overall, this review should help understanding the determinants of horse temperament/personality traits and their implication in terms of choice of the appropriate horse for a given owner, better management and training for a better welfare and horse-human relationship. Genetic influences may lead to different susceptibilities to the same environmental conditions which mean that there are no such thing as “bad” or “good” horse temperaments but rather different horse types that may require different management or training schedules. |
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Visser, E. K., Ellis, A. D., & Van Reenen, C. G. (2008). The effect of two different housing conditions on the welfare of young horses stabled for the first time. Applied Animal Behaviour Science, 114(3), 521–533.
Abstract: The effect of stabling for the first time on the behaviour and welfare of young and naïve horses has not yet been studied in detail. In this study we examined the effect of two typical housing systems on their subsequent behavioural and physiological responses upon first time stabling. Thirty-six 2-year-old Dutch warmbloods, 18 geldings and 18 mares were included in the study. Half of the horses were stabled in individual stables (10.5m2) and the other half in pair housing (48m2 for two horses). The study lasted 12 weeks. At the end of the study the physiological and temperamental responses of the horses on the different treatments was tested using a CRF challenge test (to test the HPA-axis function) and a Novel Object test (to test temperamental differences) respectively. Especially in the first week after stabling pair housed horses spent more time eating whereas individually housed horses spent more time either standing vigilant or sleeping. Stress-related behaviours like neighing, pawing, nibbling and snorting were all displayed significantly more frequently in the individually housed horses (P<0.01). At the end of the study 67% of the individually housed horses was seen performing one or more stereotypies (P<0.01). The cortisol response and ACTH response on the CRF challenge test were lower for horses in the individually housed boxes. It is suggested that this depression in socially isolated animals is caused by a desensitisation of the HPA axis in response to stress-induced elevations in ACTH and cortisol. In general there was no effect of the treatment on the reactivity of the horses during the Novel Object test. However, there were significant relations between the responses of horses in the Novel Object test and in the stable environment. It is concluded that sudden isolated stabling is stressful to young and naïve horses, resulting in a high prevalence of stereotypies and abnormal behaviours. This study also provided some support for the notion that social stress in horses may be associated with a blunted adrenocortical response to CRF challenge. The finding that responses of horses to a behavioural test are correlated with home environment behaviours suggests that individual horses exhibit consistent behavioural traits across different contexts, and opens the possibility of using behavioural tests in horses to predict more general underlying behavioural characteristics.
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Thiruvenkadan, A. K., Kandasamy, N., & Panneerselvam, S. (2008). Coat colour inheritance in horses. Livestock Science, 117(2-3), 109–129.
Abstract: The colours of the horses have long been a subject of interest to owners and breeders of horses as well as to scientists. Though, the colour of horses has little to do with its performance, it is a primary means of identification and also the first indicator of questionable parentage. Probably the ancestral colour of the horse was a black-based pattern that provided camouflage protection against predators. Horse colours are mostly controlled by genes at 12 different loci. The three basic colours of horses are black, bay and chestnut. The genetic control of the basic colours of horses resides at two genetic loci, namely Extension (E) and Agouti (A) loci. Among the basic colours bay is dominant to black and both are epistatic to chestnut. Dilution of basic colours of horses as a result of four colour dilution genes such as cream dilution, dun, silver dapple and champagne resulted in extensive array of possible colours of horses. The most widespread and familiar of the horse colour dilution gene is the one that produces the golden body colour and are called as palomino or buckskin based on the colour of the points. The grey coat colour is due to the presence of dominant gene (G) at the grey locus. Grey is epistatic to all coat colour genes except white and a grey horse must have at least one grey parent. Roan is due to a dominant gene (Rn) at roan locus and this combines with any base colour to produce the various shades of roan pattern. White coat is due to a single dominant gene (W) and it is epistatic to the genes controlling all other colours. White marking in the face and legs are due to genetic and non-genetic factors. Several genes are involved in producing white markings. During recent years, comparative genomics and whole genome scanning have been used to develop DNA tests for different variety of horse colours. Molecular genetic studies on coat colour in horses helped in identification of the genes and mutation responsible for coat colour variants. In future, this will be applied to breeding programmes to reduce the incidence of diseases and to increase the efficiency of race horse population.
Keywords: Horse; Coat colour; Melanogenesis; Genetic control; Molecular genetics
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Flauger, B., & Krueger, K. (2008). Ecology and evolution of equine cognitive abilities. In IESM 2008.
Abstract: The cognitive abilities of social ungulates, in particular horses, have widely been neglected. Preliminary results suggest that horses are capable of social cognition which they acquire through social learning. They gain information from the observation of the interaction of a conspecific and a human experimenter, and adjust their own behaviour towards the experimenter with respect to the observed horse"s reaction and relative dominance status (Krueger and Heinze, 2007). Horses are a highly social species that still exists in different evolutionary stages: domestic horses, feral horses and wild horses (Przewalski horses). Additionally, domestic and wild horses differ in their individual social behaviour. For example, in social interactions Przewalski horses appear to act significantly more aggressively than domestic horses. Therefore studies on horses are particularly suitable to investigate whether convergent social evolution favours convergent cognitive evolution. By a comparative study concerning their reasoning abilities in a specific situation, we will attempt to determine the influence of domestication and feralisation on the evolution of social cognition and to investigate possible differences in their abilities to cope with stressful situations. We started to observe the behaviour of domestic and wild horses, in particular during the integration into new social groups, especially in relation with their knowledge of the social structure of new groups and their own relative social status. Selected agonistic interactions will be measured and statistically evaluated. Additionally, the stress level of the horses will be determined by an analysis of stress hormone levels, particularly cortisol metabolites, in plasma, saliva and faeces.
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Søndergaard, E., & Turner, K. C. (2008). Timeframe for a novel horse to become familiar in a group. In IESM 2008.
Abstract: The case of familiarity in equine husbandry is not a topic that has suffered vast amounts of examination. During their lifetime domestic horses will most likely experience multiple changes in their social environment such as being sold, moved, and sent to training amongst other things. In recent years a considerable amount of studies have shown the benefits of group-housing on horses, and familiarity timeframes are of genuine importance in management of such systems.
It is our intension to determine the timeframe a novel horse faces before it is recognized as being familiar in an already established group, what factors are of importance and the level of injuries sustained in the introduction period. 24 2-year old Danish Warmblood fillies were used for this study in two blocks of 12 horses. The familiar horses, titled the K-group, consisted of 16 horses and the U-group, the unfamiliar horses, of 8. The horses came from different studs to ensure no prior contact between the two groups of test animals. They were all raised in stable group-housing systems and thereby accustomed to social interactions between conspecifics. Prior to pairing the K-horses up, nearest-neighbour observations was performed in the holding paddock to ensure the two horses were in fact familiar and would act as an established group. 8 groups of 3 individuals, 2 familiar and 1 unfamiliar, were held in separate paddocks measuring 80x80m. The horses were within eyesight of the other groups but were not able to have any physical contact. Behavioural observations were performed for 20 minutes per group upon letting the U-horse enter, and then for one hour per group (3x20mins) every Monday, Wednesday and Friday the following 16 days. On day 0, 1, 2, 4, 8 and 16 they were tested for individual preference within the group, and on test day 1 and 16 any injuries sustained were also noted. Dominance rank within the groups was determined by a group-feeding test on the last day of observation. Preliminary results from the first block indicate an overall timeframe of 6-7 days for familiarity to develop, established by observational data such as fading of greeting behaviour and decrease in distance between the three horses in the respective groups. It was also indicated that aggression between horses in the groups is not determined by familiarity but by dominance rank. Results from the full experiment will be presented. |
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Pesenti, M. E., Spinelli, S., Bezirard, V., Briand, L., Pernollet, J. - C., Tegoni, M., et al. (2008). Structural Basis of the Honey Bee PBP Pheromone and pH-induced Conformational Change. J Mol Biol, 380(1), 158–169.
Abstract: The behavior of insects and their perception of their surroundings are driven, in a large part, by odorants and pheromones. This is especially true for social insects, such as the honey bee, where the queen controls the development and the caste status of the other individuals. Pheromone perception is a complex phenomenon relying on a cascade of recognition events, initiated in antennae by pheromone recognition by a pheromone-binding protein and finishing with signal transduction at the axon membrane level. With to the objective of deciphering this initial step, we have determined the structures of the bee antennal pheromone-binding protein (ASP1) in the apo form and in complex with the main component of the queen mandibular pheromonal mixture, 9-keto-2(E)-decenoic acid (9-ODA) and with nonpheromonal components. In the apo protein, the C terminus obstructs the binding site. In contrast, ASP1 complexes have different open conformations, depending on the ligand shape, leading to different volumes of the binding cavity. The binding site integrity depends on the C terminus (111-119) conformation, which involves the interplay of two factors; i.e. the presence of a ligand and a low pH. Ligand binding to ASP1 is favored by low pH, opposite to what is observed with other pheromone-binding proteins, such as those of Bombyx mori and Anopheles gambiae.
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Corballis, M. C. (2008). Of mice and men – and lopsided birds. Cortex, 44(1), 3–7.
Abstract: The article by Zucca and Sovrano (2008, this issue) represents part of a new wave of studies of lateralization in nonhuman species. This work is often in conflict with earlier studies of human cerebral asymmetry and handedness, and the associated claim that these asymmetries are uniquely human, and perhaps even a result of the “speciation event” that led to modern humans. It is now apparent that there are close parallels between human and nonhuman asymmetries, suggesting that they have ancient roots. I argue that asymmetries must be seen in the context of a bilaterally symmetrical body plan, and that there is a balance to be struck between the adaptive advantages of symmetry and asymmetry. In human evolution, systematic asymmetries were incorporated into activities that probably are unique to our species, but the precursors of these asymmetries are increasingly evident in other species, including frogs, fish, birds, and mammals – especially primates.
Keywords: Cerebral asymmetry; Handedness; Evolution; Laterality
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Lansade, L., & Bouissou, M. - F. (2008). Reactivity to humans: A temperament trait of horses which is stable across time and situations. Appl. Anim. Behav. Sci., 114(3-4), 492–508.
Abstract: The aim of this study was to test the existence of a “reactivity-to-humans” trait which is stable over time and across situations. For this purpose, four test situations were repeated on the same animals at 8 months, 1.5 years (N = 110 horses) and 2.5 years of age (N = 54 horses). These situations involved a “familiar passive human test” during which a familiar person stayed motionless in the test pen, a “familiar active human test” and an “unfamiliar active human test” during which a familiar or unfamiliar person attempted to touch the horse, and a “halter-fitting and heart-rate measurement test”, during which the horse was haltered and equipped with a surcingle and then had its heart-rate measured. Many behavioural variables were recorded during the tests, and correlations between ages and variables measured during other situations were investigated. When correlations were found, we concluded that the variables corresponded to temperament traits which are stable over time and across situations. The horses tested were divided into four groups according to breed (Anglo-Arab and Welsh) and year of birth (2001 and 2002). Data for each group were analysed separately with Spearman rank correlations. Regarding stability over time, there was a strong correlation between ages in the frequency of licking/nibbling the passive human, the time taken by a familiar or unfamiliar person to touch the horse, and the time taken to fit a halter (e.g. the time taken to touch the horse's muzzle was significantly correlated between ages in 7 out of the 8 possible cases: 0.40 <= R <= 0.67). Regarding stability across situations, results indicate that the more frequently a horse sniffed, licked or nibbled a passive human, the easier it was for either a familiar or unfamiliar active human to touch and halter it. Moreover, a horse which could be touched easily by a familiar human could also be touched and haltered easily by an unfamiliar human. These behaviours, which are linked directly to humans, therefore indicate good stability over time and across situations. In conclusion, this stability suggests the existence of a “reactivity-to-humans” temperament trait, whether the human is passive or active, familiar or unfamiliar. When the animals do not have frequent contact with humans, this reactivity is stable over time and can be measured as early as 8 months of age using the behavioural variables cited above.
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Jørgensen, G. H. M., Borsheim, L., Mejdell, C. M., & Bøe, K. E. (2008). Social interactions and spacing in horses (Equus caballus) grouped according to gender. In IESM 2008.
Abstract: The aim of this study was to investigate the social behaviour and spacing between horses when grouped according to gender in homogeneous- or heterogeneous groups, and to see if the amount and severity of aggression differed in relation to gender composition.
A total of 66 horses divided in six batches were used. In 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. Three batches were performed on Icelandic horses and three batches on riding horses and -ponies. After 4-6 weeks of acclimatisation, a trained observer recorded all social interactions using direct, continuous observation one hour in the morning and one hour in the afternoon for three consecutive days. In addition, the nearest neighbour of each horse was recorded using instantaneous sampling every 10 minutes. The horses were inspected for injuries before grouping, day one after grouping and after 4-6 weeks. Furthermore, a novel object test and a handling test (taking horse out of group) were conducted after the behavioural observations were completed. No significant effect of gender composition was found on social interactions, spacing or injuries. Most of the aggressive interactions recorded were threats, and not aggressive interactions involving physical contact. Aggression seemed to increase with decreased space per animal and more horses per feeding place. Very few injuries were found and most were superficial. Horses showed a low degree of fearfulness in the novel object test and most horses were easy to handle in the “horse out of group test”. In conclusion, gender composition does not seem to have any effect on aggression level, spacing or injuries in social groups of horses. |
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Val-Laillet, D., Passille, A. M. de, Rushen, J., & von Keyserlingk, M. A. G. (2008). The concept of social dominance and the social distribution of feeding-related displacements between cows. Appl. Anim. Behav. Sci., 111(1-2), 158–172.
Abstract: The aim of this study was to determine the extent to which the classical properties of social dominance describe the pattern of feeder-related displacements with groups of cattle. We also compared the advantages and disadvantages of three dominance indices for describing the competitive success at the feeder. We observed displacements at the feeder within six groups of 12 lactating dairy cows over 72 h per group. We demonstrated that the cattle in our experiment established a quasi-linear hierarchy at the feeder where many dominance relationships were bi-directional (52.0 +/- 5.9%); namely, dominance relationships were significantly linear (P < 0.05 in five of the six groups) but contained many circular triads (45.0 +/- 5.6%). Dominance rank influenced the milk production (r = 0.36, P = 0.002) and the time budget of the animals: high-ranking cows were found spending more time at the feeder during the 120 min following provision of fresh food than low-ranking cows (P = 0.022), but dominance indices based on the occurrence of displacements at the feeder did not correlate with actual time spent at the feeder. The presence of numerous circular triads and bi-directional relationships suggests that the classical properties of social dominance do not correspond to the pattern of displacements that occur at feeders within small groups of cattle. Instead, the competitive success may also be affected by motivation or persistence by the animal to gain access to the food resource.
Keywords: Cattle; Social dominance; Competitive success; Hierarchy; Feeding competition
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