Most of you with horses know that horses are capable of sleeping standing up because of a stay apparatus in their rear legs.  However, they can only go into what’s called slow wave sleep while standing.  Horses must lie down, preferably on their sides, to achieve paradoxical sleep. Paradoxical sleep is the stage where complete muscular relaxation occurs. 

Many of today’s horses spend a large amount of time in stalls for various reasons.  A recent study was performed in Denmark to determine if the type of stall bedding has any influence on the amount of time horses spend lying down.  This is important because if horses are unable to enter a deep sleep, it could have an effect on their welfare and performance.  There are many different types of stall bedding used for horse stalls. 

Two of the most common types of bedding used are straw and wood shavings.  They are both economical and easy to obtain.  Straw is easy to store, but may be labor intensive.  Straw can also be dusty and cause respiratory problems, especially in allergic horses.  Also, my major concern with straw bedding is that it can be eaten by the horse and lead to colic.  Wood shavings are generally not eaten by the horse, but must be kept clean and should not be used with newborn foals.  To determine the bedding preference of horses, the Denmark study monitored the patterns of 15 horses in a stable over a 2-night period.  The time horses spent down in sternal recumbancy was approximately the same regardless of bedding type.  However, the time horses spent down on their sides, which allows them to go into paradoxical sleep, was 3 times longer for horses on straw versus shavings.  Although it seems straw is the best bedding for sleep, the researchers also found the more the horse the lies down, the greater chance the horse could get cast against a wall.