May 11, 2026, 2:40 pm | Read time: 3 minutes
Horses spend many hours a day eating–and for good reason. Their digestive system is designed for nearly constant food intake. What many horse owners underestimate: Too little hay can have serious consequences for health and well-being. Why hay is more than just a filler and how much a horse actually needs daily is explained by PETBOOK.
Horses are Natural Grazers
Horses have historically spent up to 16 hours a day eating. Since their stomach is relatively small compared to their size, they consume many small portions of food. In the past, they ate enormous amounts: around 50 to 60 kilograms of fresh grass per day. However, the water content must always be subtracted from fresh grass. This results in a food intake equivalent to about 10 to 12 kilograms of dry matter–a value that still serves as the basis for horse feeding today. 1
How Much Hay Does a Horse Need Per Day?
To determine the individual amount of hay for each horse, the so-called hay formula is used: at least 1.5 to 2 kilograms of hay per 100 kilograms of the animal’s body weight.
A large horse weighing 600 kilograms therefore needs nine to twelve kilograms of hay daily. But beware: This amount is considered the absolute minimum. The calculation only describes the maintenance requirement, meaning the state without additional work or training. For higher energy needs, horse owners should consult a veterinarian.2,3
Hay is the Foundation of Every Horse’s Diet
Hay is far more than just a filler. It provides essential roughage, which the horse converts into energy in the large intestine with the help of microorganisms. Unlike humans, a large portion of a horse’s life energy comes from this fiber digestion. Therefore, hay and grass are the foundation of every feeding plan.
For horses with low workloads and high-quality hay, concentrated feed can even be completely omitted. Supplementary feeds such as carrots, apples, or beets provide additional vitamins–especially during the grazing-free period.4
Why Long Feeding Breaks Can Cause Illness
Horses produce stomach acid around the clock. It is neutralized only by saliva–and saliva is produced only when chewing. If the stomach remains empty for more than four hours, the acid attacks the stomach lining. Possible consequences can be stomach ulcers or colic.
For this reason, it is crucial that horses have continuous access to roughage. More pasture time, open stable housing, and a constant supply of hay can help prevent physical and psychological damage.
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How Should Hay Be Fed?
Horses prefer to eat as their ancestors did–close to the ground. Hay nets should therefore not be hung too high, but should be securely fastened to prevent injuries. As a guideline, the maximum height for troughs and waterers is 0.3 times the horse’s withers height. Roughage should always be offered, especially before concentrated feed.
Hay is Not an Extra, But the Minimum
Those wondering how much hay a horse eats per day should realize: The recommended amount is not a luxury, but the physiological minimum. Too little hay endangers not only digestion but also the behavior and well-being of the horse. High-quality hay in sufficient quantity remains the most important building block for healthy and species-appropriate horse care.