12 
X. 0. Agricultural Experiment Station 
ANALYSES OF FEEDS 
Moisture 
Two samples of about three grains each of' the substance is put into weighing bottles 
with ground glass covers. These are put into an electric oven and heated for five 
hours at 110 degrees C. After heating the bottles are allowed to cool, then weighed, 
heated again, and reweighed. This is continued until the weight is constant to 2 mg. 
From the loss of weight the percentage of dry matter is calculated and the percent 
of moisture is determined 
Ether Extract 
A moisture-free sample is taken, representing about two or three grams of the sub¬ 
stance. This is put into an extraction thimble. This thimble is placed inside of a 
soxhlet. extraction siphon that is then connected to a Liebig condenser. This is then 
connected to a weighed extraction flask or bulb containing about 75 cc. of anhydrous 
ether. The extraction is continued for about two hours in an electric oven air bath. 
The extracting flask or bulb is then put in a still and the excess of ether is recovered. 
The extraction flask is put into the electric oven and dried for one hour at 100 degrees 
C., removed from the oven and placed in a desiccator, cooled and weighed. 
This process of heating and weighing is continued until the minimum weight of fat 
is calculated. 
Crude Fiber 
The residue from the ether extract determination is put into a 500 cc. flask to 
which is added 200 cc. of boiling 1.25 percent of H 2 SO 4 . This is connected to a 
condenser and boiled continuously for thirty minutes. This is filtered through a linen 
filter and washed with boiling water until the washings are no longer acid. The resi¬ 
due is then put back into the flask with 200 cc. of boiling 1.25 percent N a OH free 
as possible from sodium carbonate, and is boiled continuously for thirty minutes in 
the same manner as given for boiling with the acid. The alkaline solution is filtered 
at once and washed as rapidly as possible, and continued until the washings are neutral. 
The residue is dried at 110 degrees C. until it ceases to lose weight, weighed, inciner¬ 
ated completely, and weighed again. The loss of weight is considered to be the crude 
fiber. 
Total Proteins 
A sample of 0.7 grams of the substance is put into a Kjeldahl digestion flask, to 
which is added 10 gms. of powdered potassium sulphate, 0.7 gm. mercuric oxide, and 
25 cc. H2SO4. This mixture is then subjected to a slow heat for five minutes and a 
high heat for twenty minutes, or until digestion is complete. This is done under a 
hood. The liquid is then allowed to cool and to it is added 200 cc. of nitrogen-free 
water and a few pieces of copper wire. The flask is taken to the Kjeldahl distilling 
apparatus and 50 cc. of a saturated sodium hydroxid and 20 cc. of a potassium sul¬ 
phate solution is added. The apparatus is then connected to the condenser. The 
content of the flask is mixed by shaking. One hundred fifty cc. are then distilled into 
a standard acid solution. The standard acid solution is then titrated and the percent 
nitrogen determined and this multiplied by 6.25 gives the amount of protein. 
Ash 
Two grams of the substance is weighed into a crucible, burned at a slow heat for 
twenty minutes, then fast heat until all of the carbon is burned, and a constant weight 
is maintained. Then the percent of ash is determined. 
Nitrogen-Free-Extract 
The nitrogen-free-extract is determined by difference. 
