Midterm - Lecture 3 Flashcards
At what temperature is dry matter calculated?
60-100 C
How is dry matter calculated?
- weigh sample
- place in an oven 60-100 degrees C overnight
- weigh again the next day
- Dry weight/starting weight X 100 = % DM
How is fat content calculated?
using an ether extraction
the weight before ether extraction - weight after ether extraction
What is fat equal to?
ether content
How is crude fiber calculated?
- reflux extraction of ether extract residue with acid and base
- it stimulates the passage through the stomach and then the duodenum
- residue left after this treatment is crude fiber
How is crude protein calculated?
% nitrogen by Kjeldahl method on a separate portion of the feed sample
What is crude protein equivalent to?
nitrogen X 6.25
Why is the crude protein calculation not exact on the amount of protein in the feed?
can give a protein value for things that are not protein such as urea and melamine
What is ash?
all inorganic material, contains minerals
What is Nitrogen Free Extract?
NFE = starches and = carbohydrates
How is NFE calculated in dry matter?
NFE = 100 - % protein - % fat - % ash - % crude fiber
How is NFE calculated in as fed?
NFE = 100 - % water - % protein - % fat - % ash - % crude fiber
What is NFE not useful for?
herbivores because it does not take in account the cell walls and cytosol that is present in a herbivores diet
How much metabolizable energy do dogs get from the Atwater constant for fat?
Atwater = 9.4 kcal GE/g
Metabolizable Energy = 9 kcal ME/g
How much metabolizable energy do cats get from the Atwater constant for fat?
Atwater = 9.4 kcal GE/g
Metabolizable Energy = 8.5 kcal ME /g
