Capybaras Eat Their Cecotropes to Increase the Amount of Protein and Other Nutrients They Get from Their Low Nutrient Diet. Capybaras do not eat their faeces or their poo! They eat their cecotropes.
The capybara diet is highly fibrous and nutritionally low in value. Cecotrophy allows the capybara to digest more nutrients from an otherwise low nutrient diet and maximise the absorption of protein. The ‘cecotrophy’ excreta is different in composition to the usual oval shaped faeces, and contains up to 37% more protein and 30% less fibrous material, depending on the diet. Cecotrophy in capybaras varies in frequency and it can even stop altogether when the capybara’s diet is rich in protein.
Cecotrophy is most frequent when the nutritional quality of the diet is low. In wild populations there is a higher occurrence of cecotrophy during the dry season when food is scarce and lacking nutrients. Capybaras, with their highly efficient mastication and long retention time of undigested compounds in the cecum, can efficiently digest fibrous feedstuffs. (In rabbits large particles are barely fermented and the effect of cecotrophy on fibre digestibility is low.)
It was very interesting watching Ayu. She spent a little while (5 or more minutes) eating her cecotropes. She then moved away. About 40 or so minutes later she came over to me and sat just out of reach. About 15 minutes after this she spent a similar amount of time eating her cecotropes for a second time. Then she settled down again. About 15 minutes later she passed wind, and had one last brief ‘mouthful’. This was about midday.
The average retention time of roughage in the digestive tract of capybaras is 12 (+/- 1.9) hours.
The process by which cecotropes are produced is called “hindgut fermentation”. Food passes through the esophagus, stomach, small intestine, where nutrients are initially absorbed ineffectively, and then into the colon. Through reverse peristalsis, the food is forced back into the cecum where it is broken down into simple sugars (i.e. monosaccharides) by bacterial fermentation. The cecotrope then passes through the colon, the anus, and is eliminated by the animal and then reingested. The process occurs 4 to 8 hours after eating. This type of reingestion to obtain more nutrients is similar to the chewing of cud in cattle.
Capybaras most often practice cecotrophy in the early morning hours when protein content is highest.
In their natural habitat, 70% of the capybaras diet consists of grasses, including aquatic grasses and sedges. Capybaras spend 31% of the day grazing during the wet season, and 42% of the day grazing during the dry season as there is less food and it is less nutritious.