Lecture 3 Flashcards
What 3 nutrients provide energy?
Carbohydrates
Fats
Proteins
What doesnt supply energy?
Water
Vitamins
Minerals
What does bomb calorimeter measure?
Gross energy of feedstuff
Define eneryg
Capacity to do work
Metabolic fuel which allows the animal to perform all of the metabolic functions
What actually gets measured in bomb calorimeter?
Heat produced
What is a calorie?
Amount of heat required to raise temperature of 1 g of wter 1 degree celsisu
How many calories does Kcal =?
1000
How much is Mcal?
Mcal = 1000Kcal = 1million Calories
What is BTU?
British Thermal Unit
- amount of heat required to rais temp of 1lb of water 1 degree F
What is a joule?
Work done by a force of 1 Newton exerted through a distance of 1 meter
1 calorie = 4.184 joules
Define gross energy
Amount of heat released when a substance is completely oxidized in a bomb calorimeter
GE = Heat of Combustion
Do we use gross energy to form diet?
NO, NEVER, a lump of coal has gross energy
4 sources of energy loss
Feces
Urine
Gaseous products of digestion
Heat
How do we measure fecal energy?
Make a pellet out of feces and combust it in bomb calorimeter
What is degestible energy?
Gross energy - Fecal Energy
What does metabolizable energy take into account?
Urinary loss (UE)
Gasseous products of digestiong (GPD)
ME = DE - (UE + GPD)
What gasses are lost as sources of energy loss?
Methane
Hydrogen
Hydrogen Sulfide
CO
What do we use for the following to generate a ration formulation
Pig
Digestible Energy
- Losses of gas and urine low in pig
What do we use for the following to generate a ration formulation
Poultry
Metabolizable energy
- urinary loss is small h/e cant measure feces loss without taking in to account urine loss
What do we use for the following to generate a ration formulation
Ruminants
Metabolizing Energy
Measurement of net energy?
NE = ME - Heat increment
What is net energy?
Refers to the part of the feed that is completely useful to the animal to maintain itself or to produce meatn, milk eggs, etc
Two forms of measuring heat loss
Direct Calorimety - very expensive
Indirect Calorimetry - Uses gas exchnge to estimate heat loss
Measuring O2 consumbed and CO2 produced heat production can be estimated
What does TDN stand for?
Total digestible nutrients
What does TDN =
TDN = DCP + DCF + DNFE + (DEE x 2.25)
TDN is usually expressed as a percentage of the ration
50% TDN is not as good as 80% TDN
What five factors affect TDN?
% Dry Matter
Digestibility of Dry Matter
Amount of Fat
Amount of Ash
Species Fed
What does TDN roughly estimate?
DE
Convert TDN to DE
1 kg of TDN = 4.4 kcal of DE
What does 76% TDN = in kg/tonne TDN?
76% TDN = 760 kg/tonne TDN
