|Yen, Jong Tseng|
Submitted to: Encyclopedia of Animal Science
Publication Type: Book / Chapter
Publication Acceptance Date: 12/17/2003
Publication Date: 11/1/2004
Citation: Yen, J. 2005. Digestion and absorption of nutrients. In: Pond, W.G., Bell, A.W., editors. Encyclopedia of Animal Science. Marcel Dekker,Inc., New York, NY. p. 285-287.
Technical Abstract: Animals obtain nutrients from feed to maintain their body functions. Proteins, fats, and complex carbohydrates in feed must be broken down through physical and chemical means into simple units. The simple units are transported across the intestinal epithelium to provide energy and building blocks for the body and its secretions. The process of breaking down complex nutrients into more basic units is called digestion. The process of transporting the basic units, minerals, vitamins, and water across the intestinal epithelium is called absorption. The two processes occur within the digestive tract. The two major challenges facing animal agriculture are manure disposal and odor control. These environmental concerns are created primarily by the inefficiency in digestion, absorption, and metabolism of dietary nutrients by the animal and over supply of nutrients in the diet to maximize individual animal performance. To be environmentally friendly and socially responsible, animal research should be directed toward improving digestive and metabolic efficiency of dietary nutrient utilization by the animal, optimizing the accretion of wholesome, nutritious and tasteful animal products, and minimizing nutrient excretion and odor emission.