The intestines of herbivores are far longer in proportion to their body length than those of carnivores. Carnivores have small intestines equal to 3 to 6 times their body length. Herbivores have small intestines equal to 10 to 12 times their body length, in some cases even longer.
Compared to vegetable matter, meat is relatively easy to digest. Much of the digestion of meat takes place in the stomach before passing it to the small intestine where nutrients are absorbed. Plants contain a lot of indigestible fibers, and in order to extract the nutrients, herbivores must use the bacteria that live in their gut to break down cellulose and other materials. In addition, the herbivore's longer intestine increases the amount of surface area available for absorbing the extracted nutrients.