- 
qt 
3 
A STUDY OF RATIONS FED TO MILCH COWS. 29 
The first part of the upper table gives a reference number of 
each animal, its breed, age, weight and number of months since 
last calf. ‘The smallest daily milk flow, the greatest daily milk 
flow and the average daily yield of milk for the period of the test 
are given in the next three columns. In the three following 
columns are given the lowest, highest and average percentages 
of fat found in the daily milk of each cow for the period. 
The figures were obtained by adding together the several daily 
determinations and taking the average, hence this actual average 
is not always half way between the highest and lowest. The 
yield of fat is given in the last three columns of the first or upper 
part of the table. The minimum and maximum yields of fats 
were obtained by multiplying each day’s milk by its percentage 
of fat; the lowest number thus obtained gives the minimum daily 
yield of fat, and the largest the maximum yield of fat. It is to 
be noted that these numbers are not the same as would have 
been obtained by multiplying the minimum and maximum daily 
milk flow by the minimum and maximum percentages of fat. 
The second, or lower part of each table, gives the kinds and 
amounts of the different feeding stuffs eaten per day per 7,000 
pounds live weight, and the weights of the total and digestible 
nutrients (protein, fat and carbohydrates) which they furnished. 
As stated previously, all of the different feeding stuffs used in 
these rations were analysed, and from the results of these analy- 
ses the weights of the total nutrients furnished by the different 
coarse fodders and concentrated foods were obtained. The 
results of these analyses are given on pages 17-20 of this Report. 
The method employed in calculating the fuel value or potential 
energy furnished by the different foods, is referred to on page 17 
of this Report. 
The weights of digestible nutrients in the rations were obtained 
from the weights of total nutrients by the use of factors (coefh- 
cients of digestibility) obtained from the results of digestion 
experiments in this countryand Germany. ‘The following figures 
are taken from a paper* in which the results of nearly all Ameri- 
can and other digestion experiments are summarized. 

* Report of this Station for 1893, pp. 156-167. 

