Digestive Strategy of the Asian Colobine Genus Trachypithecus.

The Asian colobines, Trachypithecus obscurus and T. cristatus, cat plant-based diets containing 55-80% leaves. The structural polysaccharides in leaves and other plant parts require microbial fermentation before they can be used as an energy source by the monkeys. The major compartments of the gastro-intestinal tract of Trachypithecus are a voluminous haustrated stomach, a long small intestine and capacious haustrated hindgut, all of which contribute to the digestive strategy of these two species. Results of digesta marker passage studies indicate there is prolonged retention of digesta for fermentation in both the stomach and haustrated colon. The digestive strategy of these colobines is defined as gastro-colic fermentation, unlike that of other forestomach fermenters in which the hindgut fermentation is of secondary importance.