Digestion and Absorption of Carbohydrates and Nitrogenous Matters in the Hindgut of the Omnivorous Nonruminant Animal

Abstract

Introduction The large intestine constitutes an entity with particular digestive, secretory and absorptive functions. This is due to its anatomical location relative to the rest of the digestive tract as well as to the volume and length of its reservoirs. Complex contents coming from the proximal parts of the digestive tract and composed of unabsorbed dietary residues, digestive secretions and microorganisms are reaching the large intestine where they are mixed with the organ's own secretions. All these contents representing very moist substrates rich in nitrogen, energy and minerals are highly favorable to an intense development of an active microflora. The large intestine contains the largest bacterial populations (I to 3 × 10¹⁰ bacteria/g fresh content) and the greatest number of microbial species in the gut (Ducluzeau and Raibaud, 1975; Schaedler, 1973). In the colon of man this flora represents 1.5 kg net weight (Hill and Drasar, 1975). In the absence of enzymatic production by the mucosa of the large bowel (Isshiki et al., 1974), the enzymes of its microflora complete the possible remnant action of those of the small bowel with the aim of breaking down the remaining substrates. Copyright © 1978. American Society of Animal Science . Copyright 1978 by American Society of Animal Science.