Written by Sharon Smith MSc SEBC(Reg) IEng BHSAPC
Group turnout is mentally and physically stimulating and can improve the willingness of a horse to perform . There is now overwhelming evidence that permanent individual stabling/housing causes chronic stress, manifested as both visible (stereotypical behaviour, hyper-reactivity) and invisible (hypo-reactivity, learned helplessness) behaviour. But, owners fear that group housing/turnout will result in serious physical injury. That is, indeed, a risk. Some observe their horse to be more stressed when allowed free contact with other horses, and they may be correct. In this blog we’ll be looking at how social behaviour influences our management decisions. Where is the balance, in domestic environments?
Owners seem to be most concerned when they see:
Researchers use agonistic interaction to determine ‘dominance’. However, there is no constant struggle to be ‘top dog’ over the entire herd – it uses too much energy. There is no evidence for horses wanting to be in charge of decision-making when we interact with them, nor that our attempts to mimic body language is intrinsically understood . Rather, ‘dominant’ is a label for which individual in a pair gains access to a limited resource on a set occasion. An individual may be more highly motivated for food, water, sex, space to rest, shelter, or friendship at any given point in time. Motivation differs for each resource, and so can dominance – depending upon the situation the researcher uses to assess it. The limitations we create within the environment are therefore highly influential on the amount of agonistic and aggressive interactions.
Play and ‘allo-grooming’ (mutual grooming) have been evaluated for ‘ethological need’ . A ‘need’ is defined as any common, self-rewarding behaviour that has a ‘rebound’ effect, following a stressful period of denial or restriction. There was not enough evidence that play was a ‘need’. Perhaps because it too broadly defined in the study to encompass diffusing conflict (external), as well as internally driven play/exploration.
But mutual-grooming was found to be a ‘need’. In the absence of another horse, owners can also offer wither-scratches both on the ground and under saddle to reduce clinical signs of anxiety , although humans do not always allow it to be ‘mutual’. This tells us horses are more strongly driven to form close trusting friendships than play or fight. Work in semi-feral Konik horses suggests they do seem to associate most closely with others of the same sex and reproductive state, rather than age or whether they were related . This is an encouraging result, when we consider the usual livery rules around keeping geldings and mares in separate groups. Close friendships can cause different challenges. A horse may try to chase off another if their pair-bond is seen interacting with them . Intervention, by way of obstruction and body-blocking, has been observed with humans collecting a pair-bond from the paddock . Separation anxiety between pair-bonds can be resolved through very careful training.
Even breeding stallions have been successfully turned out in a large group of nine, which was widely reported at the time of publication . The initial care taken in achieving a successful outcome was less well reported. Prior to the turnout experiment, the stallions were individually housed in adjacent pairs for 14 days. The stable construction allowed mutual grooming. The stallions also worked together in harness and hind shoes were removed. Care was taken to ensure there was little competition for food or shelter, and ample forage was provided in winter. The stallions were not within sight of mares from their field and arguably the space provided for each stallion was more generous than in most domestic environments (1.1 acre per stallion), but still a tenth of that for the semi-feral Konik herd .
From a practical point of view owners can use what we know about herd dynamics to improve welfare and reduce stress:
The social behaviour and social network of horses is a complicated picture and I recommend the reader review the links provided for more detail. Most are available in full online.
 Werhahn, H., Hessel, E. F., & Van den Weghe, H. F. (2012). Competition horses housed in single stalls (II): effects of free exercise on the behavior in the stable, the behavior during training, and the degree of stress. Journal of Equine Veterinary Science, 32(1), 22-31. Link:
 Henshall, C., & McGreevy, P. D. (2014). The role of ethology in round pen horse training—A review. Applied Animal Behaviour Science, 155, 1-11.
 VanDierendonck, M. C., & Spruijt, B. M. (2012). Coping in groups of domestic horses–Review from a social and neurobiological perspective. Applied animal behaviour science, 138(3), 194-202. Link: https://www.paardenwelzijnscheck.nl/app/webroot/files/ckeditor_files/files/Gezondheid%20en%20gedrag/VanDierendonck%20%26%20Spruijt%20(2012)%20Coping%20in%20groups%20of%20domestic%20horses%20-%20Review%20from%20a%20social%20and%20neurobiological%20perspective.pdf
 Thorbergson, Z. W., Nielsen, S. G., Beaulieu, R. J., & Doyle, R. E. (2016). Physiological and behavioral responses of horses to wither scratching and patting the neck when under saddle. Journal of Applied Animal Welfare Science, 19(3), 245-259.
 Bouskila, A., Lourie, E., Sommer, S., de Vries, H., Hermans, Z. M., & van Dierendonck, M. (2015). Similarity in sex and reproductive state, but not relatedness, influence the strength of association in the social network of feral horses in the Blauwe Kamer Nature Reserve. Israel Journal of Ecology & Evolution, 61(2), 106-113. Link: https://s3.amazonaws.com/academia.edu.documents/44706809/Bouskila_et_al._2016_Similarity_in_sex_and_reproductive_state_influence_association_strength_in_social_network_of_horses.pdf?AWSAccessKeyId=AKIAIWOWYYGZ2Y53UL3A&Expires=1514918584&Signature=kf13mULNReoGLXkzdn1dJjysRsM%3D&response-content-disposition=inline%3B%20filename%3DSimilarity_in_sex_and_reproductive_state.pdf
 Smith, S. unpublished observation.
 Briefer Freymond, S., Briefer, E. F., Niederhäusern, R. V., & Bachmann, I. (2013). Pattern of Social Interactions after Group Integration: A Possibility to Keep Stallions. Link: