Stereotypic Behavior in Pastured HorsesBy Kentucky Equine Research Staff · April 20, 2015
Weaving, cribbing, stall walking, pawing the ground, and walking or running fences are classified as stereotypies, or repetitive behaviors that serve no purpose. Other stereotypies include oral behaviors like licking or eating dirt, chewing bark or fences, and chewing or eating bedding.
More prevalent in stalled horses, stereotypies are thought to be a result of boredom or lack of social contact. Pastured horses may also exhibit these behaviors but usually on a much less frequent basis.
In a presentation given at a recent equine conference,* Australian researchers reported on a study that attempted to relate stereotypical behavior in pastured horses to pasture management and feeding practices.
Survey responses were tallied from 497 respondents who were the owners of 3,082 horses. Among the horses, 85% had at least 16 hours of pasture time per day. Almost half of the horses displayed some type of stereotypical behavior, with 26% chewing bark, 18% licking or eating dirt, and 7% pawing the ground. Half of the owners used pastures of 2 hectares (5 acres) or less, and another 42% used pastures up to 10 hectares (25 acres). Horses were generally turned out in groups of two to four.
A large majority (90%) of owners reported some problems with their pastures including overgrazing, soil compaction, growth of weeds, and waterlogged areas. The problems, all of which are indicative of too many horses on too little area, were found with a similar frequency in smaller and larger pastures. Concentrates and/or supplements were provided to 95% of the horses, and 86% were given some sort of conserved forage in addition to grazing.
The researchers pointed out that modern horse management often allows horses very few challenges or decision-making opportunities. Humans decide what the horses will eat, when they will be fed, and where and how long they will graze. Forage is limited, and ranging over a large area to find better pasture is impossible. Herdmates are also selected by humans. This management style, though necessary for the available land and the uses horses are put to, is still far from a natural existence, and this fact may cause stress that is expressed as stereotypical behavior. Further study may clarify the relationship of management strategies and stereotypies in horses.
*“Relative occurrence of stereotypic type behaviours in pastured horses in Australia” was presented at the 2014 Australasian Equine Science Symposium.