Lecture 3

Question 1

What 3 nutrients provide energy?

Answer 1

Carbohydrates

Fats

Proteins

Question 2

What doesnt supply energy?

Answer 2

Water

Vitamins

Minerals

Question 3

What does bomb calorimeter measure?

Answer 3

Gross energy of feedstuff

Question 4

Define eneryg

Answer 4

Capacity to do work

Metabolic fuel which allows the animal to perform all of the metabolic functions

Question 5

What actually gets measured in bomb calorimeter?

Answer 5

Heat produced

Question 6

What is a calorie?

Answer 6

Amount of heat required to raise temperature of 1 g of wter 1 degree celsisu

Question 7

How many calories does Kcal =?

Answer 7

1000

Question 8

How much is Mcal?

Answer 8

Mcal = 1000Kcal = 1million Calories

Question 9

What is BTU?

Answer 9

British Thermal Unit

• amount of heat required to rais temp of 1lb of water 1 degree F

Question 10

What is a joule?

Answer 10

Work done by a force of 1 Newton exerted through a distance of 1 meter

1 calorie = 4.184 joules

Question 11

Define gross energy

Answer 11

Amount of heat released when a substance is completely oxidized in a bomb calorimeter

GE = Heat of Combustion

Question 12

Do we use gross energy to form diet?

Answer 12

NO, NEVER, a lump of coal has gross energy

Question 13

4 sources of energy loss

Answer 13

Feces

Urine

Gaseous products of digestion

Heat

Question 14

How do we measure fecal energy?

Answer 14

Make a pellet out of feces and combust it in bomb calorimeter

Question 15

What is degestible energy?

Answer 15

Gross energy - Fecal Energy

Question 16

What does metabolizable energy take into account?

Answer 16

Urinary loss (UE)

Gasseous products of digestiong (GPD)

ME = DE - (UE + GPD)

Question 17

What gasses are lost as sources of energy loss?

Answer 17

Methane

Hydrogen

Hydrogen Sulfide

CO

Question 18

What do we use for the following to generate a ration formulation

Pig

Answer 18

Digestible Energy

• Losses of gas and urine low in pig

Question 19

What do we use for the following to generate a ration formulation

Poultry

Answer 19

Metabolizable energy

• urinary loss is small h/e cant measure feces loss without taking in to account urine loss

Question 20

What do we use for the following to generate a ration formulation

Ruminants

Answer 20

Metabolizing Energy

Question 21

Measurement of net energy?

Answer 21

NE = ME - Heat increment

Question 22

What is net energy?

Answer 22

Refers to the part of the feed that is completely useful to the animal to maintain itself or to produce meatn, milk eggs, etc

Question 23

Two forms of measuring heat loss

Answer 23

Direct Calorimety - very expensive

Indirect Calorimetry - Uses gas exchnge to estimate heat loss

Measuring O2 consumbed and CO2 produced heat production can be estimated

Question 24

What does TDN stand for?

Answer 24

Total digestible nutrients

Question 25

What does TDN =

Answer 25

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

Question 26

What five factors affect TDN?

Answer 26

% Dry Matter

Digestibility of Dry Matter

Amount of Fat

Amount of Ash

Species Fed

Question 27

What does TDN roughly estimate?

Answer 27

DE

Question 28

Convert TDN to DE

Answer 28

1 kg of TDN = 4.4 kcal of DE

Question 29

What does 76% TDN = in kg/tonne TDN?

Answer 29

76% TDN = 760 kg/tonne TDN