digestion

Question 1

what are the three main factors that losses are associated with

Answer 1

digestion
absorption
metabolism

Question 2

digestibility definition

Answer 2

proportion of feed that is not excreted

Question 3

4 losses of feed energy

Answer 3

feces
urine
methane
heat increment

Question 4

what is the most important factor affecting digestibility

Answer 4

fiber

Question 5

factors affecting digestibility

Answer 5

nutrient composition
plant species
within species differences
forage maturity
level of intake
associative effects
processing roughages
temperature

Question 6

are annual or perennial grasses generally more digestible

Answer 6

annual

Question 7

T/F Legumes are generally more digestible than grasses

Answer 7

TRUE

Question 8

grass digestibility ranking

Answer 8

legumes > cool season > warm season

Question 9

within species differences affecting digestion

Answer 9

-leaf:stem ratios
-amount of lignin(GMO v non GMO)

Question 10

how does plant maturity effect digestibility and quantity

Answer 10

as plant maturity increases so does quantity, but digestibility decreases

Question 11

why does digestibility decrease as the plant ages

Answer 11

the cell wall becomes thicker

Question 12

what effect does plant maturity have on feed intake

Answer 12

as plant maturity increases
feed intake decreases

Question 13

how much is digestibility decreased per each multiple increase in feed intake

Answer 13

4%
EX 12 lb : 70% digestible
24 lb : 66% digestible

Question 14

T/F decrease in digestibility due to feed intake occurs in all species

Answer 14

FALSE. happens most severely in ruminants

Question 15

T/F associative effects only impact reminants

Answer 15

TRUE

Question 16

what is an example of a positive associative effect

Answer 16

low-quality forage fed with cottonseed meal.
CSM gives microbes energy to better digest forage

Question 17

what happens to digestibility when you process roughage? why? what happens to feed intake?

Answer 17

digestibility decreases.
feed spends less time in the GI tract
feed intake increases

Question 18

what happens to digestibility and feed intake when you process grains

Answer 18

digestibility increases
feed intake decreases

Question 19

T/F both heat and cold stress have an impact on digestibility

Answer 19

FALSE. heat stress seems to have no impact on digestibility

Question 20

what is the change in digestibility as temperatures decrease

Answer 20

digestibility decreases

Question 21

what forms of energy loss does TDN not account for

Answer 21

urine
methane
heat increment