Ashley Griffin, University of Kentucky

Roughage is an important part of the equine diet.

Horses have an absolute requirement for long-stemmed roughage. They require it for normal gastrointestinal function. Adequate roughage will go a long way toward preventing digestive disorders. Horses should be fed a minimum of 0.75 to 1 percent of their body weight per day in roughage. That means a 500 kg horse would require 5 kg (11 lb) of roughage per day. If adequate roughage is not supplied in the horse's diet, behavioral disorders occur, such as wood chewing, eating feces or bedding, and chewing the manes and tails of other horses. Insufficient roughage also predisposes the horse to the potentially deadly gastrointestinal disorder called colic.