Gastric acid

In the horse’s stomach, a strong acid, hydrochloric acid (HCl), is continuously produced. It is therefore commonly referred to as “stomach acid”. In horses, it is not produced in the initial part of the stomach, but only in the mucus-protected fundus region. The bacteria that carry out digestive work in the first section of the stomach must be inhibited, or strongly restricted in their proliferation and activity, in the second section by the action of hydrochloric acid. Otherwise, undesirable fermentation and gas formation would occur. Harmful microorganisms from the environment are also killed by the stomach acid.

In addition to hydrochloric acid, the gastric juice also contains the protein-splitting enzyme pepsin. Together, both bring about the first step of protein digestion.

The better the feed mash is mixed with acidic gastric juice in the second section of the stomach, the more acidic the pH value of the feed mash, and the better the inhibition of bacteria. With pure hay feeding, the physiological pH value at the stomach outlet is < 3.

Excessive amounts of grain per meal cause excessive bacterial fermentation in the first part of the stomach. This results in increased amounts of volatile fatty acids, which attack the unprotected stomach wall. In addition, the compact grain mash cannot be sufficiently mixed with gastric juice in the second section of the stomach. Bacterial activity persists, which can lead to digestive disorders.

If feeding breaks last longer than 4 to 6 hours, no buffering saliva reaches the stomach for too long a period. This can lead to “hyperacidity” in the stomach and to gastric ulcers.

The horse is designed for “continuous feeding”. The continuous intake of small amounts of feed, well chewed and mixed with saliva, ensures the trouble-free function of the horse’s stomach and the digestive organs that follow.