Feed Energy

Question 1

what is feed energy

Answer 1

property of nutrients (nutrient adjacent)

Question 2

what nutrients supply energy

Answer 2

carbohydrates
lipids
proteins

Question 3

gross energy

Answer 3

potential energy of a feed
provides limited information on actual energy

Question 4

why is gross energy not a good measure of true energy

Answer 4

doesn’t account for losses or digestibility
EX. corn and hay have similar gross energy

Question 5

how do you measure gross energy

Answer 5

bomb calorimeter(heat of combustion)

Question 6

equation for digestible energy(DE)

Answer 6

gross energy - fecal loss

Question 7

why are DE and TDN similar in accuracy

Answer 7

they don’t account for losses from methane, urine, and heat increment

Question 8

average fecal energy loss in pigs

Answer 8

3-10%

Question 9

average fecal energy loss in horses

Answer 9

10-40%

Question 10

average fecal energy loss in high grain fed ruminants

Answer 10

10-30%

Question 11

average fecal energy loss in high roughage fed ruminants

Answer 11

40-60%

Question 12

how are DE and TDN different

Answer 12

DE uses bomb colorimeter
TDN uses proximate analysis

Question 13

equation for metabolizable energy

Answer 13

DE - Urine energy - methane

Question 14

equation for net energy

Answer 14

ME - heat increment

Question 15

what is the most accurate estimate of feeds energy value

Answer 15

net energy

Question 16

what is heat increment

Answer 16

heat of digestion/eating/metabolization

Question 17

when is the only time heat increment is useful

Answer 17

during cold stress

Question 18

which has a higher heat increment: roughage or grains?

Answer 18

roughage

Question 19

what can you feed to lower stress/heat increment

Answer 19

fat

Question 20

NEm

Answer 20

net energy used for maintenance

Question 21

NEg

Answer 21

net energy used for growth

Question 22

NEI

Answer 22

net energy used for milk production

Question 23

NEp

Answer 23

net energy used for fetal development

Question 24

why do cows have lower heat increment than horses

Answer 24

enzymatic cost of ruminating is less than eating

Question 25

how is heat production measured

Answer 25

indirect-respiratory calorimeter
measure CO2 that goes in vs. CO2 that comes out

Question 26

how is the heat intake caused by different feedstuff measured

Answer 26

feed is fed at one amount and heat produced is measured
feed is then fed a t a higher amount and heat produced is measured again
the steeper the line produced the higher the heat increment

Question 27

why will feeds high in fiber CHO have lower NE values that feeds high in starch CHO

Answer 27

bc fiber causes higher fecal, methane and heat increment losses