Any foodstuff that contains at least 18% crude fiber can be classified as a forage. Forage is an essential part of the horse's diet and can come from pasture, harvested feeds like hay, and even food byproducts like beet pulp. As a minimum two thirds of a horse's diet, by weight, should consist of forage. Some show horses get by with only one half of the diet being forage, but they are at increased risk for colic, founder, and stable vices.

Getting enough good quality forage in a horse's diet can present a problem. The season, weather, large amounts of storage space required, tooth problems, heaves (COPD), and pregnancy may all contribute to finding adequate amounts of suitable forage. This article consists of an overview of available forages, their nutritional characteristics, and how they may be used in a feeding program.

Horses evolved grazing forages. Not only are forages an important source of all the nutrients a horse requires but the very act of grazing, chewing, and digesting forages is important to a horses feeling of well being. Forages provide energy, protein, minerals, and vitamins, but unlike other sources of these nutrients forages provide fiber. A list of benefits horses derive from fiber is:

• Adequate chewing time which prevents boredom.
• Energy
• Motility
• Substrate for bacterial digestion in the cecum
• Create a feeling of satiation in the horse
• Becomes a water reservoir in the large bowel

To the horse this means adequate forage provides all the essential nutrients, helps prevent colic, founder, and even some of the common stable vices that stem from boredom or a feeling of unease. Earlier we stated forages ought to make up at least 2/3rds a horse's diet on a dry matter basis. Stated from a different point of view forages should be fed at around a minimum of 1.5% bodyweight (dry matter basis). But these are really saying the same thing since a horse will eat a total of about 2.5 % of their bodyweight a day: 2/3 (2.5%) = appx. 1.5% as a minimum amount of forage. The horse that eats just forage, and no concentrates, is going to eat 2.5% a day in forage if given the food free choice.