Recent research suggests that providing stabled horses with more than one type of forage, may reduce the risk of straw impaction colic.
Feral horses eat a diet consisting of a wide variety of grasses, herbs and other plants. In contrast, most stabled horses are fed hay as their main source of forage. The restricted access to pasture that many horses experience may be associated with stereotypic behaviour such as crib-biting and weaving.
Debbie Goodwin, Nell Davidson and Pat Harris conducted a study to see if there was a difference in behaviour between horses fed a single type of forage and those fed several different forages. Twelve horses in a competition Dressage and Eventing yard were used in the trial. They were routinely stabled except for a maximum of four hours at pasture.
Two identical stables were used in the trial. Each was 12 feet square, bedded with straw, and contained two water buckets. One stable contained a single hay net of high quality meadow hay. The other, in addition to the hay, contained five proprietory forages.
Horses were introduced to each of the two boxes on two coccasions and their behaviour was recorded over a period of five minutes, using a wall mounted video camera. The researchers then measured the time spent on feeding and other activities by examining the recordings.
All six forages were eaten. Hay was the least popular forage. Horses spent more time foraging in the multiple forage stable than they did in the stable in which only hay was provided. The difference, however, was not statistically significant. Horses spent significantly more time eating the straw bedding in the single forage stable. They also showed significantly more searching behaviour in the single forage box ( ie they spent more time moving and looking out of the box ).
The authors conclude that, in this short term study, providing multiple forages reduced both the amount of straw eaten and the time spent on behaviour which suggested frustration.
"The horses appeared to enjoy having a choice of forages" said Dr Pat Harris. "If these effects persist over longer periods, providing more than one forage could reduce the incidence of straw impaction colic in stabled horses, and provide other welfare benefits through enrichment of the environment."
For more details see: D Goodwin, H P B Davidson, P Harris. Behavioural enrichment for stabled horses using multiple forages. Proceedings of the Third International Congress on Veterinary Behavioural Medicine. 2001