DAIRY HUSBANDRY 
21 
EXERCISE NO. 13 
Object: To determine the effect of temperature on the reading of the fat 
column. 
Procedure: “A difference of 40° F. in temperature when reading a fat 
column obtained in the case of a 10% milk, will make a differ¬ 
ence in the reading of .14%.” (F. & W. \\ 41, footnote.) 
A. Test a sample of milk in duplicate in the usual way. 
B. Remove the bottles from the tester and place in a water bath 
at 100° F. Read after 3 minutes. 
C. Place the bottles, after reading, in a water bath at 140° F. 
Read after 3 minutes. 
D. Place the bottles, after reading, in a water bath at 180° F. 
Read after 3 minutes. 
Note: Be sure to have the upper surface of the fat column 
beneath the surface of the water in the water bath. 
Observations: 
Sample 
Temperature 
of water bath 
% fat 
Color 
Condition 
1 
a 
b 
2 
a 
b 
3 
a 
b 
Conclusions: 
Questions: (1) If the graduations of a test bottle measure 2.3 cc. from 
0-10%, what would be the correct test of a sample of milk 
which reads 3.7% fat in this bottle? 
(2) Mention at least six causes of variations in the test of a cow’s 
milk. 
(3) How do changes in the feed of a cow influence the quantity and 
the quality of her milk? 
(4) How does the test of the milk yielded by a cow generally 
change with the advance of the period of lactation? 
References: F. & W. If 159-163 inclusive, 174-177 inclusive, 41 42; 
Van S. pp. 1-8, 66-67; Jud. pp. 30-59, 69-70; St. pp. 41-68. 
