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Wehnert, C., Schmidt, A., Möstl, E., Aurich, J., Müller, J., & Aurich, C. (2008). Heart rate and cortisol release in horses during road transport. In IESM 2008.
Abstract: In sport horses, equestrian competitions may lead to increased cortisol release. The competition itself but also a new environment or transport to the events can be considered as stressors. In this study, warmblood sport horses (4-16 years, 4 mares, 2 stallions, 18 geldings) were transported by road for one (t1), 3.5 (t3.5) and 8 hours (t8), (n=8 per group). Heart rate (HR) is an indicator of stress and correlates with cortisol release. Heart rate was recorded with a mobile recording system (f810i, Polar, Kempele, Finland), fixed to a girth around the thorax of the horse and was monitored the day before transport, during transport and 12 hours thereafter. In addition, cortisol metabolite concentrations in faeces were determined in order to analyse adrenocortical activation during transport. Faecal samples were collected three times per day. Cortisol metabolite concentrations in faeces are increased approximately 24 hours after an elevation in plasma cortisol concentrations. Basal HR before transport did not differ between groups (45±2 (SEM) beats/min). During the first 30 min of transport, HR increased significantly (84±6, p<0.001, Kruskal-Wallis-H-test) but did not differ between groups. During the remaining part of the transport, HR was 61±6 beats/min (p<0.001 vs. first 30 min). When HR was analysed for the last 30 min of transport, values for groups t1 and t8 were significantly (p<0.05) higher than in group t3.5. HR decreased to baseline values within less than 30 min after transport and did not differ between groups (30-60 min after transport: 44±3 beats/min). Faecal cortisol metabolite concentrations on the day after transport were elevated compared to pre-transport baseline values in all three groups of horses. Significant differences existed between groups (e.g. 18 hours after transport t1: 91±5, t3.5: 110±18, t8: 136±27 ng/g; p<0.05). Based on HR analysis, horses of group t3.5 had adapted to transport, while the prolonged transport in group t8 again was a stressor. In group t1, which was transported only for one hour, the higher heart during the last 3 min of transport was still part of the initial rise in HR. After an initial increase, heart decreases indicating adaptation of the horse to transport. Cortisol metabolite concentrations in faeces indicate that transport causes adrenocortical activation with the amount of cortisol released depending on the duration of transport. Transport over medium distances appears to no major stressor and a negative impact on the performance of the horse is unlikely. Transport over 8 hours caused the most pronounced cortisol release and HR increases again during the last hours of an 8-hour transport. Transports exceeding this time may temporarily affect the subsequent performance of the horse in equestrian sports.
Supported by Stiftung Forschung für das Pferd
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Streit, S., Zeitler-Feicht, M. H., & Dempfle, L. (2008). Gibt es in der Gruppenhaltung von Pferden bei der Abruffütterung am Automaten mehr Auseinandersetzungen als bei der Fütterung in Fressständen? [Keeping horses in groups, are there more confrontations when feeding is done with automatic feeding systems than with feeding stalls?]. In KTBL-Schriften (Vol. 471). KTBL.
Abstract: Das Droh- und Meideverhalten von 270 Pferden wurde im Fressbereich von 10 Offenlaufställen
mit Fressständen und 11 Offenlaufställen mit computergesteuerten Abrufstationen
anhand von visuellen kontinuierlichen Direktbeobachtungen erfasst. Diese erfolgten je Betrieb
über einen 24-Stunden-Tag, der nach dem Tortenstückverfahren (6x4 Stunden) zusammengesetzt
war.
Insgesamt wurden 6297 agonistische Verhaltensweisen in, vor und hinter den
Fütterungseinrichtungen registriert (Meiden 40,6 %, Verdrängen 12,8 %, Beißen/ Hinterhandschlag/
Angehen 12,7 % und Drohen/ Drohbeißen/ Hinterhanddrohen 33,9 %). In den
Futterstationen wurden 22,5 % dieses Verhaltens beobachtet, vor und hinter den Futterstationen
77,5 %. Bei den Betrieben mit Fressständen fanden 31 % der agonistischen Verhaltensweisen
in den Ständen statt, bei den Betrieben mit Abruffütterung 21 %.
Der Einfl uss des einzelnen Betriebes (innerhalb Fütterungssystem) auf die agonistischen
Verhaltensweisen vor und hinter den Fütterungseinrichtungen war signifi kant. Die Auswertung
ergab, dass Drohgesten im Wartebereich von Abrufstationen häufi ger auftreten
als in dem von Fressständen. Demgegenüber können Pferde in Abrufstationen ungestörter
fressen. Insgesamt betrachtet war jedoch die Anzahl an sozionegativen Interaktionen im
Bereich der Futtereinrichtungen bei beiden Fütterungssystemen gering. Die agonistischen
Verhaltensweisen wurden zusätzlich noch von der Heumenge und dem Konstitutionstyp
beeinfl usst.
Der Betrieb erwies sich als maßgeblicher Einfl ussfaktor. Als Resümee ergibt sich, dass
bei ordnungsgemäßer Gruppenhaltung mit fachgerechtem Management beide Fütterungssysteme
für Pferde im Offenlaufstall geeignet sind.
[The threatening and avoiding behaviour of 270 horses living in run-out sheds was observed
at 10 stables with feeding stalls and at 11 stables with automatic feeding systems for hay
and concentrates. Every group of horses was observed on five succeeding days visually
and immediately for 6 sessions, each of 4 hours. These 6 slices form together 24 hours, a
complete day.
Altogether, 6297 agonistic behaviour patterns were registered in front of, inside and
behind the feeding stations (avoiding behaviour 40.6 %, edging out of others 12.8 %,
Auseinandersetzungen an automatischer Abruffütterung und Fressständen
KTBL-Schrift 471 79
biting/rear leg kicking/charging 12.7 % und threatening/biting threats/rear leg kicking
threats 33.9 %). 22.5 % of these types of behaviour were recorded in the feeding stations,
77.5 % together in front and behind of these. In the stables with feeding stalls there were
31 % of the observed threatening gestures inside the feeding stations, in the stables with
automatic feeders only 21 %.
The individual farm showed signifi cant infl uence on the modes of agonistic behaviour
in front and behind the feeding facilities. Threatening gestures happen more often in the
waiting area of automatic feeders than in that of feeding stalls. On the other hand horses
in computer controlled systems will be less disturbed at eating. All together the number
of negative interactions in the feeding area at both feeding systems was relatively low.
In addition the agonistic behaviour was infl uenced by the quantity of hay and the constitutional
typ of the horses.
Because of the management of the individual stable exercises the most substantial
infl uence on the behaviour of the horses, it can be said, that, correct group keeping with
professional management provided, both feeding systems are suitable for horses in run-in
sheds.]
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Geutjens, C. A., Clayton, H. M., & Kaiser, L. J. (2008). Forces and pressures beneath the saddle during mounting from the ground and from a raised mounting platform. The Veterinary Journal, 175(3), 332–337.
Abstract: The objective was to use an electronic pressure mat to measure and compare forces and pressures of the saddle on a horse's back when riders mounted from the ground and with the aid of a mounting platform. Ten riders mounted a horse three times each from the ground and from a 35 cm high mounting platform in random order. Total force (summation of forces over all 256 sensors) was measured and compared at specific points on the force-time curve. Total force was usually highest as the rider's right leg was swinging upwards and was correlated with rider mass. When normalized to rider mass, total force and peak pressure were significantly higher when mounting from the ground than from a raised platform (P < 0.05). The area of highest pressure was on the right side of the withers in 97% of mounting efforts, confirming the importance of the withers in stabilizing the saddle during mounting.
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Smith, B. R., & Blumstein, D. T. (2008). Fitness consequences of personality: a meta-analysis. Behav. Ecol., 19(2), 448–455.
Abstract: The study of nonhuman personality capitalizes on the fact that individuals of many species behave in predictable, variable, and quantifiable ways. Although a few empirical studies have examined the ultimate consequences of personality differences, there has been no synthesis of results. We conducted a formal meta-analysis of published studies reporting fitness consequences of single personality dimensions to identify general trends across species. We found bolder individuals had increased reproductive success, particularly in males, but incurred a survival cost, thus, supporting the hypothesis that variation in boldness was maintained due to a “trade-off” in fitness consequences across contexts. Potential mechanisms maintaining variation in exploration and aggression are not as clear. Exploration had a positive effect only on survival, whereas aggression had a positive effect on both reproductive success and, not significantly, on survival. Such results would suggest that selection is driving populations to become more explorative and aggressive. However, limitations in meta-analytic techniques preclude us from testing for the effects of fluctuating environmental conditions or other forms of selection on these dimensions. Results do, however, provide evidence for general relationships between personality and fitness, and we provide a framework for future studies to follow in the hopes of spurring more in-depth, long-term research into the evolutionary mechanisms maintaining variation in personality dimensions and overall behavioral syndromes. We conclude with a discussion on how understanding and managing personality traits may play a key role in the captive breeding and recovery programs of endangered species.
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Powell, D. (2008). Female–female competition or male mate choice? Patterns of courtship and breeding behavior among feral horses (Equus caballus) on Assateague Island. J. Ethol., 26(1), 137-144.
Abstract: Previous research on the Assateague horses found that high-ranking females had more surviving offspring than low-ranking females. Variance in reproductive success may be the result of a variety of proximate processes that affect sexual behavior such as mate choice and mate competition. A study was done to determine whether patterns of courtship, social, and sexual behavior could be identified that would suggest mate choice and/or mate competition. Behavioral data were collected from approximately 40 sexually mature mares living in harem bands. Stallions showed more interest in the eliminations of dominant mares than subordinate mares. Males also engaged in significantly more high-intensity (e.g., mounts and copulations) sexual behavior with dominant mares than subordinate mares, and there was a trend for males to engage in more low-intensity (e.g., flehmen and ano-genital sniffing) sexual behavior with dominant mares than subordinate mares. There was no effect of mare rank on spatial relationships with the stallion; however, dominant mares did attempt to restrict reproductive access to the stallion by harassing and disrupting copulations. Higher foaling rates among dominant mares on Assateague Island could therefore be the result of rank-related mate choice by stallions and direct female competition for mating opportunities.
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Hemelrijk, C. K., Wantia, J.,, & Isler, K. (2008). Female Dominance over Males in Primates: Self-Organisation and Sexual Dimorphism. PLoS ONE, 3(7), e2678.
Abstract: The processes that underlie the formation of the dominance hierarchy in a group are since long under debate. Models of self-organisation suggest that dominance hierarchies develop by the self-reinforcing effects of winning and losing fights (the so-called winner-loser effect), but according to ‘the prior attribute hypothesis’, dominance hierarchies develop from pre-existing individual differences, such as in body mass. In the present paper, we investigate the relevance of each of these two theories for the degree of female dominance over males. We investigate this in a correlative study in which we compare female dominance between groups of 22 species throughout the primate order. In our study female dominance may range from 0 (no female dominance) to 1 (complete female dominance). As regards ‘the prior attribute hypothesis’, we expected a negative correlation between female dominance over males and species-specific sexual dimorphism in body mass. However, to our surprise we found none (we use the method of independent contrasts). Instead, we confirm the self-organisation hypothesis: our model based on the winner-loser effect predicts that female dominance over males increases with the percentage of males in the group. We confirm this pattern at several levels in empirical data (among groups of a single species and between species of the same genus and of different ones). Since the winner-loser effect has been shown to work in many taxa including humans, these results may have broad implications.3
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Lansade, L., Bouissou, M. - F., & Erhard, H. W. (2008). Fearfulness in horses: A temperament trait stable across time and situations. Appl. Anim. Behav. Sci., 115(3-4), 182–200.
Abstract: The purpose of this study was to test the existence of a “fearfulness” trait in horses, by testing the stability across situations and over time of the responses to different fear-eliciting situations. It was also to identify which behavioural parameters are the best indicators of this trait. Sixty-six Welsh ponies and 44 Anglo-Arab horses were successively tested at 8 months and 1.5 years of age. Of these, 33 Welsh ponies and 21 Anglo-Arabs were also tested at 2.5 years of age. At each age, they were subjected to four test situations. The first test involved the introduction of a novel object in the test pen (novel object test). In the second test, a novel area was placed in the pen between the horse and a bucket of food, to determine the time the horse took to cross the area (novel area test). Finally, the third test consisted in suddenly opening an umbrella in front of the horse while it was eating (surprise test). During these tests, many behavioural parameters were recorded. A fourth test consisted of a surprise test during which the horse was held by a handler while its heart rate was measured. Spearman correlations were used to identify links between behavioural parameters measured during different tests and between different ages. Reactions to the first three tests showed consistency between them and over time. Among all the behavioural parameters measured during these tests, some presented high stability over time and were well correlated with behaviours expressed during other tests, indicating they are the best indicators of a fearfulness trait: the frequency of licking/nibbling the novel object, the time to put one foot on the novel area and to eat from a bucket placed just behind it, and the flight distance and the time to eat under the opened umbrella. The stability across responses expressed in various fear-eliciting events and over time from 8 months to 2.5 years of age suggests the existence of a [`]fearfulness' trait in horses. The different indexes of heart rate measured or calculated during the surprise effect present limited stability over time and almost no correlation with the behavioural parameters measured during the other three tests. We conclude that, in contrast to the previously mentioned behaviours, these are not reliable measures of a temperament trait. From a practical point of view, this study shows that it is possible to identify a horse's level of fearfulness as early as 8 months of age using the first three tests.
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Komárková, M., & Dubcova, J. (2008). Factors affecting suckling behaviour in loose housed domestic horses. In IESM 2008.
Abstract: Suckling, the main part of maternal investment in equids, is crucial for development and social success of the foal. As such it is of great importance in horse breeding. We examined effect of following factors mentioned in literature on behavioural parameters of suckling in loose housed domestic horses: age and sex of the suckling foal, age, parity (primiparous/multiparous), pregnancy (yes/no) and rank of the mother and sex of the foetus if the mother was pregnant. Four variables describing suckling behaviour were modelled: proportion of suckling attempts rejected by the mother, suckling duration, frequency of suckling and proportion of suckling terminated by the mother. Further, suckling terminated by another mare were analyzed. Behavioural observations were conducted at the National Stud Kladruby nad Labem (Czech Republic). Eight groups of loose housed Oldkladruby horse mares with foals were observed from 14 days (in average) after delivery to abrupt weaning (four to six months of age), each foal for 120 days at least. Within two seasons, 10 495 suckling bouts and suckling attempts were observed in 79 foals (32 males, 47 females, mothered by 59 individual mares). Horses were studied with ad libitum sampling for 6 hours per group each 14 days. Dominance status of the mother was assessed using the Clutton-Brock index (Clutton-Brock et al. 1982, Nature 350:178-180), adjusted to the number of mares in each group, and dyadic dominance-submission relationships between all group members (mares) were determined. No significant effect of pregnancy and sex of the foetus on suckling behaviour were found, except the tendency of mothers bearing female foetuses to terminate more suckling. These findings are opposite to literature, where male foetuses were connected with higher rejection rates (Duncan et al. 1984, Anim Behav 32:255-263). However, incidence of suckling attempts rejected by the mother was very low (2.24 %). No effect of pregnancy of the mother could be caused by the stud management; horses are well fed and do not suffer for nutrition stress as horses in the wild may. All variables were negatively affected by increasing foals age (as expected). Neither sex of the suckling foal, nor age of the mother did significantly affect any of the studied variables. The higher dominance rank a mare achieved the higher frequency of other group member suckling she terminated (rs = 0.49, P < 0.0001; Spearman correlation coefficients, PROC CORR, SAS). From suckling terminated by another mare (N = 190), in 93 % (N =177) it is a dominant mare who ends the suckling. Despite these significant results, suckling terminated by another mare were negligible (1.8 % from all observed suckling bouts) and agonistic interactions between dominant and submissive mares seemed not to compromise foal development. In conclusion, in loose housed mares of domestic horse with foals we have found no detrimental effect of any of literally cited factors on suckling behaviour.
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Mirabet, V., Fréon, P., & Lett, C. (2008). Factors affecting information transfer from knowledgeable to naive individuals in groups. Behav. Ecol. Sociobiol., 63(2), 159-171.
Abstract: There is evidence that individuals in animal groups benefit from the presence of knowledgeable group members in different ways. Experiments and computer simulations have shown that a few individuals within a group can lead others, for a precise task and at a specific moment. As a group travels, different individuals possessing a particular knowledge may act as temporary leaders, so that the group will, as a whole, follow their behaviour. In this paper, we use a model to study different factors influencing group response to temporary leadership. The model is based on four individual behaviours. Three of those, attraction, repulsion, and alignment, are shared by all individuals. The last one, attraction toward the source of a stimulus, concerns only a fraction of the group members. We explore the influence of group size, proportion of stimulated individuals, number of influential neighbours, and intensity of the attraction to the source of the stimulus, on the proportion of the group reaching this source. Special attention is given to the simulation of large group size, close to those observed in nature. Groups of 100, 400 and 900 individuals are currently simulated, and up to 8,000 in one experiment. We show that more stimulated individuals and a larger group size both induce the arrival of a larger fraction of the group. The number of influential neighbours and the intensity of the stimulus have a non-linear influence on the proportion of the group arrival, displaying first a positive relationship and then, above a given threshold, a negative one. We conclude that an intermediate level of group cohesion provides optimal transfer information from knowledgeable to naive individuals.
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Croft, D. P., James, R., & Krause, J. (Eds.). (2008). Exploring Animal Social Networks. Princton: Princton University Press.
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