Lower Digestive Tract Microbiology
نویسندگان
چکیده
The lower digestive tract of animals is often referred to as the hindgut and normally denotes the large intestine, which includes the cecum, colon, and rectum. The cecum is a branch from the junction of the small intestine and colon. There is a great diversity among animals in hindgut morphology, mainly in relation to diet of the animal. Carnivores have a small hindgut and a cecum may be absent. However, herbivores, such as the horse, have a large hindgut capacity. The hindgut of nonruminant animals is the primary site for retention of food residues and endogenous substrates for microbial fermentation. Conditions in the hindgut include a constant temperature, pH between 6.5 and 7.5, and low concentrations of oxygen, thus providing an environment for 10 to 10 microorganisms of up to 400 different species per gram of lumen contents. The fermentation end products of the microorganisms—short-chain volatile fatty acids, primarily acetate, propionate, and butyrate—are absorbed throughout the hindgut and used as energy by the animal. Humans have continuously tried to influence the microbial species present in the intestinal tract with the objective to increase meat-animal production efficiency. This has occurred primarily with the use of antibiotics, prebiotics, probiotics, or other dietary additives.
منابع مشابه
Second Joint INRA-RRI Gastrointestinal Tract Microbiology Symposium Challenges for Microbial Digestive Ecology... ...at the Beginning of the Third Millennium
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