The behavioural development of a horse from birth till adulthood is a continuous process that needs the presence of certain environmental features, as well as the absence of others, to occur optimally. For some behaviour patterns (e.g. maternal bonding) exposure must occur during specific periods in order to exert an effect, but for other behaviour patterns (e.g. socialisation on conspecifics or humans) repeated exposure over an extended period appears be to necessary in order for learning to be permanent. Since these ontogenetic mechanisms seem to operate similarly under natural as well as husbandry conditions, optimal housing and management of the young developing horse is necessary in order to obtain an adult horse that reacts the way we expect it to react.
6.1. Conclusion
Group housing and handling exert a positive effect on the social behaviour and emotionality of young horses.
6.1.1. Effects of social environment
• Group housed horses exercised more than single housed horses, which may be beneficial for the development of the musculo-skeletal system.
• Group housed horses were less aggressive and their social behaviour seemed better developed that the social behaviour of single housed horses.
• Single housed horses approached sooner and can be approached more closely by people when tested in their home environment than group housed horses.
• Group housed horses tended to reach more stages in the training program than single housed horses.
• Single housed horses kicked and bit more during training than group housed horses.
• There were no effects of social environment on feed intake or growth.
6.1.2. Effects of handling
• In general no effect of handling on the reactions towards humans in approach tests.
• Handled horses are less emotional when assessed by behaviour and physiological measures than non-handled horses.
• Effects on tractability seem to depend on details of the handling, like age at handling, type of handling, duration of handling etc.
• Handling does not affect learning ability directly, but effects due to less emotionality and better tractability are observed.
• Handled horses show a lower rise in heart rate than non-handled horses when exposed to novelty.
• Handling may have a positive effect on measures such as heart rate and cortisol secretion that are known to be related to stress and immunology.
Conclusion and perspectives
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6.2. Perspectives
From the present study it appears that there is no doubt that group housing is essential for young horses in relation to their social behaviour and also beneficial in relation to their reactions in training situations. However, it is still an open question whether young horses have to stay in groups all day all year round, or if part-time group housing may have the same positive effects. Another question is how to achieve the best composition of the group. Most young horses are housed in semi-natural groups, i.e. homogenous groups where a clear leadership may be missing. It is evident that foals learn many things from the dam, e.g. food selection but it is unclear in which way a missing obvious leadership may affect the behavioural development of young horses after weaning. Another aspect of the homogenous groups is the fact that the highest ranking animal may not be psychologically capable of being a “leader”, a fact which may potentially result in a tyrannical leader. This problem has been recognised in practice but remains to be investigated in an experimental study. The use of horses in leisure and sport often requires that the horse will meet or even be housed with unknown horses. How horses are best prepared for that situation is not known. Perhaps some regrouping during the socialisation period is beneficial. Additionally, adult horses will often be on their own and therefore it may be useful for young horses to learn to be separated from other horses in various situations.
Likewise, there is no doubt that handling of young horses has a positive effect in relation to their later life as companions in leisure or sport. However, there are still some open questions in relation to the long term effects of handling and details of the handling scheme. Focus in many experiments has been concentrated on the time at which handling is conducted, but it may be that it is not so much the specific time at which handling takes place but rather that handling is repeated with certain intervals over an extended period that is essential in order to achieve a permanent effect. Unfortunately, no systematic studies have been conducted to evaluate how often handling must be repeated, how long the intervals between training sessions should be, and whether the extended period should last from weaning till adulthood or whether a shorter period is sufficient. As shown in this study only 20 hours of handling during a two-year period are enough to exert some positive effects but details about the handling scheme are still unclear.
Apart from concerns about the time at which handling should be carried out and how often it should be repeated, an equally important question is what the young horse should learn in order to function satisfactorily as an adult. Obviously, socialisation in relation to humans, i.e.
learning the ability to obey commands to stand still, to lift a leg, to be led etc. is only part of what is required of a horse. Other skills such as remaining calm in traffic or when separated from its conspecifics, are equally important. Unfortunately, also in this aspect our knowledge is based primarily on practical experience rather than systematic investigation. There is little doubt, however, that in order to produce horses that fulfil the demands of future riders, we need a much better understanding of what kind of training a young horse should receive before its education as a riding horse starts.
Despite the holes in our knowledge there is no doubt from the results of the present study and other studies that group housing of young horses and probably of older horses too, should be promoted. Likewise, despite the holes in our knowledge on handling and training of horses, introducing foals to handling is far more safe than introducing an adult horse to handling; thus any positive human-animal interaction at a young age will be better than no interaction.