ANSC 4394 EXAM 2 WITH CORRECT ANSWERS 2026

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