Abstract: Highlights
�Horses remember the location of food hidden by the experimenter after a delay.
�They understand the communicative meaning of a human positioned close to the target.
�The same horses are capable of changing their decision-making strategy.
�They are able to shift from accuracy inferred from human given cues to speed.
�Horses can use human cues or not depending on time, cost, experience and reward.
Abstract
To date, horses have seemed capable of using human local enhancement cues only when the experimenter remains close to the reward, since they fail to understand the communicative meaning of the human as momentary local enhancement cue (when the human is not present at the moment of the animal's choice). This study was designed to analyse the ability of horses to understand, remember and use human-given cues in a delayed (10 s) three-choice task. Twelve horses (experimental group) had to find a piece of carrot hidden under one of three overturned buckets after seeing the experimenter hide it. The results were then compared with those of a control group (twelve horses) that had to find the carrot using only the sense of smell or random attempts. At the beginning, the experimental horses made more correct choices at the first attempt, although they took more time to find the carrot. Later the same horses were less accurate but found the carrot in less time. This suggests that the value of the proximal momentary local enhancement cues became less critical. It seemed, in fact, that the experimental and control group had aligned their behaviour as the trials proceeded. Despite this similarity, in the second half of the trials, the experimental group tended to first approach the bucket where they had found the carrot in the immediately preceding trial. Our findings indicate that horses are capable of remembering the location of food hidden by the experimenter after a delay, by using the human positioned close to the target as valuable information. The same horses are also capable of changing their decision-making strategy by shifting from the accuracy inferred from human given cues to speed. Therefore, horses are able to decide whether or not to use human given-cues, depending on a speed-accuracy trade-off.

Abstract: Introduction
Are horses doing well in their husbandries? For the first time the answer shall be given objectively by an integral on-farm welfare assessment system for horse husbandries. A current research project at the Technical University Munich evaluates indicators for well-being, pain and suffering in horses in order to develop a welfare assessment system (Baumgartner and Zeitler-Feicht 2013, 2014a, 2014b, 2015, Zeitler-Feicht et al. 2015). The research project is professionally supported by horse husbandry experts from academics, industries as well as leading organizations for horse owners and veterinarians.
The aim of the project is to develop a welfare assessment system for all horse husbandry systems which can be applied both for sport horses and for leisure horses. It is based on national animal welfare standards (BMELV 2009) and does take sustainability into consideration. Animal-based indicators are completed with resource-based indicators if necessary. It is stipulated that indicators are valid, reliable and feasible.
Welfare criteria were formulated for the two principles „good health“ and „behavioural demands“ (see figure 1 and 2). Each has to be represented by at least one indicator.
The principle „behavioural demands“ aims at the possibility for horses to practise species-specific behaviour. It is gathered to what extent the housing conditions allow the horses to live out and show species-specific behaviour. Furthermore in the present studies the frequency of selected behaviours including abnormal behaviour were collected in precise timeframes.
Potential indicators for assessing equine welfare on-farm were selected by study of literature and field tests. The field tests included direct observations on free-ranged horses, horses in group-housing systems and single-stabled horses. The following section presents selected indicators that are feasible for assessing equine behaviour on-farm.
Feasible behavioural indicators for well-being
The literature research revealed that „being together“ is linked with affiliative behaviour. It includes „resting together“, „foraging together“ and additionally „walking together“. Horses do have a strong need for social bonds. „Being-together“ amongst horses must be voluntary and not caused by bad weather conditions or lack of space. Therefore the context must be considered. For temporary direct observations the frequency in group-housing systems is sufficient (0.57 ± 0.67 per horse per 20 minutes). That´s why in our study „being-together“ is considered as a feasible indicator for well-being for horses in permanent or temporary groups. It is intended to conduct further studies on its validity.
Other behaviours such as „social play“ is not only linked with positive emotional states in adult horses. Several studies showed that horses use „social play“ as a stress relief. However, it is too seldom to collect in an on-farm assessment system. Because of the lack of feasibility and validity we excluded „social play“ as an indicator for well-being.
Feasible behavioural indicators for suffering
Horses show „abnormal behaviour“ in distress, frustration, deprivation or conflict situations. The present studies showed a relatively high frequency in single-stabled horses (3.3 ± 6.45 per horse per 20 minutes). Hence „abnormal behaviour“ is a feasible and valid indicator for suffering. However, established stereotypes need to be excluded, because they may indicate a previous welfare status rather than the current welfare status.
Horses use „agonistic behaviour“ to regulate social relations, to defend themselves or to defend resources. If husbandry or management is inadequate, „agonistic behaviour“ increases and thereby the frequency of injuries caused by social conflicts. A high frequency of „agonistic behaviour“ indicates a high aggression level in group-housed horses and therefore distress and suffering. The mean frequency of group-housed horses is sufficient for temporary observations (2.6 ± 2.26 per horse per 20 minutes). As a result „agonistic behaviour“ is a feasible and vaild indicator for suffering. Further studies need to be done on the scoring and severity.
Key words
Animal-based indicators
Equine welfare
Being-together
Abnormal behaviour
Agonistic behaviour
References
Baumgartner M. & M. H. Zeitler-Feicht (2013): Entwicklung eines Bewertungssystems zur Beurteilung der Tiergerechtheit von Pferdehaltungen als Bestandteil eines Nachhaltigkeitsmanagementsystems. KTBL Schrift: Aktuelle Arbeiten zur artgemäßen Tierhaltung 503, 226 – 227.
Baumgartner M. & M. H. Zeitler-Feicht (2014a): Indikatoren für Tierwohl beim Pferd. 7. Pferde-Workshop Uelzen 2014. DGfZ-Schriftreihe Heft 64, 161 – 166.
Baumgartner M. & M. H. Zeitler-Feicht (2014b): Entwicklung eines Bewertungssystems zur Beurteilung der Tiergerechtheit von Pferdehaltungen als Bestandteil eines Nachhaltigkeitsmanagementsystems. 9. Niedersächsisches Tierschutzsymposium in Oldenburg, Hrsg. Nds. Ministerium für Ernährung, Landwirtschaft und Verbraucherschutz, 37 – 42.
Baumgartner M. & M.H. Zeitler-Feicht (2015): Eignung ausgewählter tierbezogener Indikatoren zur Beurteilung der Tiergerechtheit von Pferdehaltungen hinsichtlich Praktikabilität. In: Tagungsband der Deutschen Veterinärmedizinischen Gesellschaft e.V. (DVG), Fachgruppen „Ethologie und Tierhaltung“ sowie „Tierschutz“, Verlag der DVG Service GmbH, Gießen, S. 182 – 192.
BMELV (2009): Leitlinien zur Beurteilung von Pferdehaltungen unter Tierschutzgesichtspunkten. Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz. Sachverständigengruppe tierschutzgerechte Pferdehaltung.
Zeitler-Feicht M.H., Frank V., Ramoser A., Seiler S., Girisch C., Baumgartner M. (2015): Anhand welcher Verhaltensweisen lassen sich Rückschlüsse auf das Wohlbefinden von Pferden ziehen? In: Tagungsband der Deutschen Veterinärmedizinischen Gesellschaft e.V. (DVG), Fachgruppen „Ethologie und Tierhaltung“ sowie „Tierschutz“, Verlag der DVG Service GmbH, Gießen, S. 148 – 156.

Abstract: Determining steroid hormone concentrations in hair has been frequently performed in humans, and increasingly in wildlife and domestic animals. Hair hormone concentrations may provide insight on how individuals are responding to their physiological condition or social situation. Cortisol is most frequently measured in hair as a biomarker of long-term stress, while testosterone may be linked with reproductive status in males. These hormones are commonly measured in substances that reflect either current (e.g. blood) or very recent (e.g. saliva, urine, feces) circulating levels. However, these hormones are also incorporated into hair during hair growth and provide a chronological record of circulating hormone levels. Thus, analysis of steroid hormones in hair provides a much longer representation of an animal’s endocrine status than other tissues frequently targeted for non-invasive monitoring.
The feral horse (Equus ferus caballus) population on Sable Island, Nova Scotia, Canada, has been annually censused during the mid-late summer since 2008 to track individual life histories and population dynamics. We collected tail hair (n = 144 females, n = 162 males) from known individuals either opportunistically or from natural or artificial snags to investigate how hair cortisol and testosterone might be associated with physiological state (e.g. lactating vs. non-lactating, body condition, age), as well as their social situation (e.g. dominant band stallion, subordinate band stallion, or bachelor) and measures of sociality. The proximal 5 cm of hair (excluding first 4mm or root region) were ground to a fine powder and hormones extracted with methanol and analyzed by using enzyme-linked immunoassay.
Preliminary analyses of the data showed a general sex based difference in hair cortisol concentrations (females lower than males; t = 3.16, df = 317, P=0.002). Among females, the presence of nursing foals was accompanied by an increase in hair cortisol (z = 2.93, df =140, P = 0.003); however, no significant difference was found in hair cortisol concentrations based on sex of the foal (t = -0.06, df = 82, P = 0.95). Horses in poor body condition tended to have higher hair cortisol than those in good or excellent condition (slope= -0.203, df = 312, P = 0.003). We also observed an increased concentration of hair cortisol as horses increased in age from 3-6 or entered into reproductive maturity. Adult male dominant band stallions did not have significantly less cortisol than bachelors or subordinate stallions but these three groups were significantly greater than young males (aged 3 and 4) who generally do not challenge the older males for reproductive opportunities.
Additionally, we looked at hair testosterone concentrations for n=46 males. Testosterone is known to influence traits and behaviours that enhance sexual selection. Often there is an inverse relationship between cortisol levels and testosterone; in particular, being able to maintain high testosterone and not have elevated cortisol related to the metabolic costs of sexual trait production ensures that traits or behaviours honestly signal the quality of the individual. For this reason we’d expect to see band stallions (those males in a position to mate) have a lower value in the ratio Cortisol: Testosterone. Early indications suggest we see this phenomenon in feral horses.
As a relatively new approach in wildlife research, the use of hair hormone analysis shows promise in contributing to our understanding of physiological aspects of sexual selection and other processes. Additionally, hair hormone analysis may have applications in advancing knowledge of animal husbandry and in particular, welfare.

Abstract: In ethical discussions, a cost-benefit analysis requires that welfare costs associated with an activity can be reliably estimated and balanced against the potential benefits of the activity to both humans and animals. The current study applies a meta-analysis to the peer-reviewed evidence for costs and benefits of hyperflexion of the neck in horses; a practice that has attracted enormous public and scientific scrutiny over the past 15 years. A literature review identified 55 studies dealing with horses’ head and neck postures. Fourty-two of these studies examined the impact of various postures on equine welfare, for example, by assessing behavior, physiological stress parameters, health or rider-horse interaction. Thirty-five studies examined the impact of various postures on gymnastics (e.g. kinematics, shifts in weight distribution, muscle activity, airway functioning or overall workload). For the meta-analysis a dataset containing information from each of the individual studies was created. Data included information such as type, degree, duration and circumstances of hyperflexion applied in that particular study as well as information on the horses (e.g., sport discipline, level of training, breed) and on the study design (e.g., size of study and experimental or epidemiological research design). The results of the study regarding the impact of hyperflexion on a) welfare and b) gymnastics were coded as positive (1), insignificant or contradictory (0) or negative (-1). The significant majority of studies (88%) concluded that a hyperflexed head and neck posture negatively impacts welfare. Just one study suggested welfare advantages of training in a hyperflexed head and neck posture. An analysis using a generalized linear mixed model to assess the influence of the above factors collated in the dataset revealed that none of these factors significantly influenced the probability of a study to detect negative welfare implications. Thus hyperflexing the neck appears to impair horses’ welfare regardless of, for example, the duration or the way of achieving hyperflexion. A concurrent assessment of the evidence for gymnastic benefits showed that approximately one quarter of studies conclude that there may be benefits, while another quarter of the studies conclude that hyperflexion has detrimental effects on gymnastics. Thus, on the costs-side there is a clear reduction in equine welfare and some undesirable gymnastic effects, as well as likely a compromised profile of the equestrian sports in public. Benefits, on the other hand, include some desirable gymnastic effects, and potentially increased control of the horse for the rider. On balance, it appears that the costs associated with hyperflexion exceed the potential benefits of the activity to both humans and horses.

Abstract: Mirror Self-Recognition (MSR) is an extremely rare capacity in the animal kingdom that reveals the emergence of complex cognitive capacities (de Waal 2008). So far, MSR has been reported only in humans, chimpanzees (Gallup, 1970), bottlenose dolphins (Reiss and Marino, 2001) and Asian elephants (Plotnik et al, 2006), all species characterized by a highly developed cognition. There is growing evidence that domestic horses posses high cognitive abilities, such as cross-modal individual recognition (Proops et al, 2009), triadic post-conflict reunion to maintain social homeostasis (Cozzi et al, 2010), complex communicative systems (Whatan and McComb, 2014), flexibility in problem-solving (Lovrovich et al, 2015), and long-term memory (Hanggi and Ingersoll, 2009). All these capacities make horses a good candidate to test the ability of MSR in a domestic species. Through a classical MSR experimental paradigm (de Waal 2008) we tested eight horses living in social groups under semi-natural conditions (from the Italian Horse Protection rescue centre). Animals showing MSR typically go through four stages (Plotnik et al, 2006): (i) social response, (ii) physical mirror inspection (e.g., looking behind the mirror), (iii) repetitive mirror-testing behaviour (i.e., the beginning of mirror understanding), and (iv) self-directed behaviour (i.e., recognition of the mirror image as self). The final stage, known as the “mark-test”, is verified when a subject spontaneously uses the mirror to check for a coloured artificial mark on its own body which it cannot perceive otherwise. The horses underwent a three-phase “mark-test”: 1) with sham mark (transparent ultrasound water gel) positioned on both side at jaw level, 2) mark (yellow eye shadow mixed with ultrasound water gel) positioned on left side of jaw (with sham mark on the right), 3) mark (yellow eye shadow mixed with ultrasound water gel) positioned on right side of jaw (with sham mark on the left)
The mirror was one 0.5-cm-thick piece of 140x220-cm plexiglass glue on wood. Each test lasted one hour, horses were tested once a day, in consecutive days and at the same time. Our preliminary result on 1 horse shows some changes in self-directed behaviours which can be attributed to presence of the coloured mark. Firstly, the presence of the coloured mark significantly increased the frequency of scratching on both sides of the muzzle (p < 0.0001). The most intriguing result (p < 0.0001) comes from the comparison of the scratching rates directed towards the coloured mark side (N = 41) and the sham mark side (N = 23). Under the control condition (i.e. sham mark on both sides) no statistical difference was found for the scratching rates directed to the muzzle sides (dx N = 8; sx N = 5). Although further analyses are needed to confirm these preliminary results, our finding opens new scenarios about the evolution of Mirror Self-Recognition. The capacity of horses to recognize themselves in a mirror may be the outcome of an evolutionary convergence process driven by the cognitive pressures imposed by a complex social system and maintained despite thousands years of domestication.
Keywords:
Domestic horse · Mark test · Socio-cognitive skills · Self-awareness
References
De Waal FBM (2008) The thief in the mirror. PloS Biol 6(8):e201
Gallup GG Jr (1970) Chimpanzees: Self-recognition. Science 167: 86-87.
Reiss D, Marino L (2001). Mirror self-recognition in the bottlenose dolphin: A case of cognitive convergence. Proc Natl Acad Sci U S A 98:5937-5942.
Plotnik J, de Waal FBM, Reiss D (2006) Self-recognition in an Asian elephant. Proc Natl Acad Sci U S A 103: 17053-17057.
Proops L, McComb K, Reby D. (2009) Cross-modal individual recognition in domestic horses (Equus caballus). Proc Nat Acad Sci USA;106:947-951.
Cozzi A, Sighieri C, Gazzano A, Nicol CJ, Baragli P. Post-conflict friendly reunion in a permanent group of horses (Equus caballus). Behav Process 2010;85:185-190.
Wathan J, McComb K. The eyes and ears are visual indicators of attention in domestic horses. Curr Biol 2014;24(15): R677-R679.
Lovrovich P, Sighieri C, Baragli P (2015) Following human-given cues or not? Horses (Equus caballus) get smarter and change strategy in a delayed three choice task. Appl Anim Behav Sci, in press.
Hanggi EB, Ingersoll JF. (2009) Long-term memory for categories and concepts in horses (Equus caballus). Anim Cogn; 12:451-462.