ANSC 4394 EXAM 2 WITH CORRECT
ANSWERS 2026
As fed (wet ; fresh) - CORRECT ANSWER --
expression of nutrient concentration of a feedstuff in the wet form of that feedstuff
Dry Matter (moisture free) - CORRECT ANSWER --
expression of nutrient concentration of a FS in the dry form of that FS
*we prefer this*
Air dry (approx 90% DM) - CORRECT ANSWER --
expression of nutrient concentration in a FS in a 90% DM basis
-For dry grains and air : air dry = as fed
Conversion calculation - CORRECT ANSWER -
%nutrient as fed/%feed dry matter=%nutrient dry matter/100% dry matter
Conversion - CORRECT ANSWER --
changing nutrient concentration of all feedstuffs to be compared to a dry matter basis allows a
ccurate comparisons of nutrient concentration of all various feedstuff
-differences in % moisture invalidates the comparison of feedstuffs on an as fed basis
-the moisture effectively dilutes the concept of nutrients in the FS
AF to DM - CORRECT ANSWER -nutrient content increases, weight decreases
DM to AF - CORRECT ANSWER -nutrient content decreases and weight increases
Digestion/metabolism trial - CORRECT ANSWER --
differences between what went in and what came out
,1. analyze feed ingredients
2. feed animal a given amount
3. collect feces
4. analyze feces
Determining a digestion coefficient for protein - CORRECT ANSWER -
Assume: Step 1: calculate weight of feed and feces collected (days X lbs collected per day)
Determining a digestion coefficient for protein (con't) - CORRECT ANSWER -
Analysis: Step 2: calculate DM consumed= total lbs for feed X % DM feed
Step 3: DM consumed X %CP feed
Step 4:DM excreted= lbs for feces X feces % DM
Step5: DM excreted X %CP feces =CP excreted
Step 6: %CP of feed consumed -
%CP of feces excreted=answer/%CP of feed consumed X 100=digestion coefficient
Step 7: %CP of feed X digestion coefficient
Ruminants - CORRECT ANSWER -Digest in rumen
%CF digested=50-90% aka EXCELLENT
Digestibility of CF by species - CORRECT ANSWER -Horse-cecum-13-40%(poor)
Pig-cecum-3-25% (poor)
Rabbit-cecum-65-78% (better)
rat-cecum-34-46%(poor)
dog-cecum-10-30% (poor)
Man-S&L Intestine-25-62(better)
Poultry-cecum-20-30% (poor)
, Feedstuff Energy Methods of Measuring - CORRECT ANSWER --
Total digestible nutrients (tdn): popular
-Calorie system:human measure this way
-roughage/concentration ratio (r/C) system
-Net energy:new
TDN - CORRECT ANSWER --
determination: use chemical analysis to determine nutrient composition to get crude compositi
on
-determine the digestibility of feed nutrients by a digestion trial to get digestion coefficent
-calculates digestible nutrients (crude composition X digestion coefficient)
-calculate TDN (%dig pro + %dig fbr + %dig NFE + %dig fat X 2.25)
TDN Advantages - CORRECT ANSWER --establish
-familiar
TDN Disadvantages - CORRECT ANSWER --
considers only digestive losses (feces ignores energy losses via urine, gases, and heat productio
n)
-not expressed in energy terminology
-% of weight vs calories
-overestimates energy value of forages, especially: poor quality forages
Net Energy Methods - CORRECT ANSWER --
energy balance trial: direct caloric measurement of energy intakes and losses
ANSWERS 2026
As fed (wet ; fresh) - CORRECT ANSWER --
expression of nutrient concentration of a feedstuff in the wet form of that feedstuff
Dry Matter (moisture free) - CORRECT ANSWER --
expression of nutrient concentration of a FS in the dry form of that FS
*we prefer this*
Air dry (approx 90% DM) - CORRECT ANSWER --
expression of nutrient concentration in a FS in a 90% DM basis
-For dry grains and air : air dry = as fed
Conversion calculation - CORRECT ANSWER -
%nutrient as fed/%feed dry matter=%nutrient dry matter/100% dry matter
Conversion - CORRECT ANSWER --
changing nutrient concentration of all feedstuffs to be compared to a dry matter basis allows a
ccurate comparisons of nutrient concentration of all various feedstuff
-differences in % moisture invalidates the comparison of feedstuffs on an as fed basis
-the moisture effectively dilutes the concept of nutrients in the FS
AF to DM - CORRECT ANSWER -nutrient content increases, weight decreases
DM to AF - CORRECT ANSWER -nutrient content decreases and weight increases
Digestion/metabolism trial - CORRECT ANSWER --
differences between what went in and what came out
,1. analyze feed ingredients
2. feed animal a given amount
3. collect feces
4. analyze feces
Determining a digestion coefficient for protein - CORRECT ANSWER -
Assume: Step 1: calculate weight of feed and feces collected (days X lbs collected per day)
Determining a digestion coefficient for protein (con't) - CORRECT ANSWER -
Analysis: Step 2: calculate DM consumed= total lbs for feed X % DM feed
Step 3: DM consumed X %CP feed
Step 4:DM excreted= lbs for feces X feces % DM
Step5: DM excreted X %CP feces =CP excreted
Step 6: %CP of feed consumed -
%CP of feces excreted=answer/%CP of feed consumed X 100=digestion coefficient
Step 7: %CP of feed X digestion coefficient
Ruminants - CORRECT ANSWER -Digest in rumen
%CF digested=50-90% aka EXCELLENT
Digestibility of CF by species - CORRECT ANSWER -Horse-cecum-13-40%(poor)
Pig-cecum-3-25% (poor)
Rabbit-cecum-65-78% (better)
rat-cecum-34-46%(poor)
dog-cecum-10-30% (poor)
Man-S&L Intestine-25-62(better)
Poultry-cecum-20-30% (poor)
, Feedstuff Energy Methods of Measuring - CORRECT ANSWER --
Total digestible nutrients (tdn): popular
-Calorie system:human measure this way
-roughage/concentration ratio (r/C) system
-Net energy:new
TDN - CORRECT ANSWER --
determination: use chemical analysis to determine nutrient composition to get crude compositi
on
-determine the digestibility of feed nutrients by a digestion trial to get digestion coefficent
-calculates digestible nutrients (crude composition X digestion coefficient)
-calculate TDN (%dig pro + %dig fbr + %dig NFE + %dig fat X 2.25)
TDN Advantages - CORRECT ANSWER --establish
-familiar
TDN Disadvantages - CORRECT ANSWER --
considers only digestive losses (feces ignores energy losses via urine, gases, and heat productio
n)
-not expressed in energy terminology
-% of weight vs calories
-overestimates energy value of forages, especially: poor quality forages
Net Energy Methods - CORRECT ANSWER --
energy balance trial: direct caloric measurement of energy intakes and losses
