How does horse extract the energy to needs from a relatively small digestive system?

Question

Recently I saw Inside nature's gaints episode on horse, and was fascinated about its internal organisation. And my question is that they have a very large lungs to accommodate, but a relatively smaller stomach. But other herbivores like the hippopotamus have a very large digestive system even though they need less energy than horse. How does horse manage this problem? How do they get that much of energy even though it had small digestive system and more over it is an herbivore?

Answer 1

Hello!

The stomach does not allow for absorption of nutrients, and only acts as a way to digest materials. In horses (and other select herbivores), the plant-like material is broken down within the cecum, which is an organ that functions like a fermentation vat. This makes the nutrients and energy more accessible for the absorption within the small intestine. The small intestine of a horse can be extremely long, and measure around 50 to 70 feet (15 to 21 meters) long! It is just wrapped up in a certain way so that it can fit neatly within the animal.