NUTR 3210 Lecture Notes - Lecture 4: Lignin, Particle Size, Bacterial Growth
4 Feb 2017
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Document Summary
Measure of the fraction of a specific nutrient (energy) that is extracted in the gi tract. Calculated form the amount of nutrient in the diet and the amount of nutrient in the feces. Represents a combination of nutrient release from the food matrix, microbial fermentation and absorption. Why is this important: prevents deficiency and ensures essential nutrients are available to the organism. Allow animal to adapt to the diet over 7-21 day period. Measure intake over a 3-10 day period. Metabolic cages collect and analyze urine and feces but they create anxiety in animals. Internal (natural component of feed: external (a component added to feces) Steps: adapt animal to test diet (include marker, collect a feed and fecal sample, analyze each for marker and nutrient of interest relative to your indicator. Advantages of this method: less labour intensive, ideal for wild animals. Not considered when measuring apparent digestibility: endogenous secretions. Epithelial cells fatty acids: bacterial growth in gut.
