Roughage

Roughage refers to feed materials rich in raw fibre, such as hay, straw and silage. Alongside grass, hay is the staple diet for horses. In the wild, a horse spends around 18 hours of its day grazing on mature grass and often covers great distances in search of feed.
It fills its relatively small stomach (capacity approximately 15 to 20 litres) and its gut slowly but continuously with small amounts. Gastric acid is therefore produced continuously – unlike in humans, where it is only produced during food intake. Long feeding breaks (over 4 hours) should therefore be avoided.
Roughage (coarse fodder) refers to feed materials rich in crude fibre, such as hay, straw and silage, which the horse has to chew for a long time and salivate thoroughly. Saliva buffers the gastric acid, and feed that has been thoroughly chewed and moistened can be digested better. Chewing is also a good occupation and important for tooth wear. Structurally effective roughage stabilises the gut biome and supports good hindgut digestion. The volatile fatty acids produced in this process are the horse’s main source of energy.

Grass (particularly young grass) is not considered roughage, as it generally contains too little structure, is eaten too quickly and chewed too little, is not sufficiently digestible in the hindgut, and does not adequately support the gut microbes. Only “old”, tall-grown grass, i.e. mature growth, comes close to meeting these requirements.

Alongside grass, hay is the staple diet for horses. Unlike hay, silage is slightly moist and therefore dust-free, making it suitable for horses with allergies. Straw is filling, but it is not suitable as a substitute for hay, as it lacks many valuable nutrients, can lead to impaction colic, and is often heavily contaminated with fungi.