36 REPORT OF DEPARTMENT OF ANIMAL HUSBANDRY OF THE 
METHODS OF SAMPLING AND ANALYSIS. 
The rations were weighed out at several different times during 
the course of the experiment, and each time this was done 
samples were taken of the various foods. 
The milk, urine and feces were taken directly to the labora- 
tory and immediately weighed and sampled, excepting that the 
night’s milk was kept in an ice box until morning, when it was 
mixed with the morning’s milk and a sample was then drawn 
from the mixture. The feces were thoroughly stirred and 
samples (4 lbs.) of the fresh material were taken for drying. 
These samples were dried over steam coils at a temperature 
ture not exceeding 60° C. 
In general the methods of the A. O. A. C. were followed in 
the analyses, the only exception being that petroleum ether was 
used instead of sulphuric ether in extracting the fats from the 
foods and feces. (See Bulletin 132.) 
Nitrogen was determined directly in fresh samples of the 
urine and feces. The drying of the feces at a temperature vary- 
ing from 50° to 60° C. caused a material loss of nitrogen, as 
previous results clearly show. (See Bulletin 1382.) 
THE RESULTS OF THE EXPERIMENTS. 
The results of these experiments are presented without a full 
statement of the data involved. 
The omissions are the daily weights and daily composition of 
the feces, urine and milk, the figures for which would occupy 
many pages and would be of use only to those who wish to 
study the data from some standpoint not considered by the 
authors. 
The points that will be discussed are the following: 
(1) The digestibility of the rations, with some reference to 
the influence upon digestibility of the proportions of nutrients 
in the case of Cow 12. 
(2) The influence of the composition of the ration upon the 
quantity and composition of the milk and upon the composition 
ef the milk fat. 
