A STUDY OF RATIONS FED TO MILCH COWS. 45 
The tables are alike in arrangement, and a description of one 
will serve for all. Each table contains the condensed results of 
a single test. Table 1, for instance, gives the statistics for test 
No. 27. 
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 maxi- 
mum 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 maxt- 
mum yield of fat. It is to be noted that these numbers are not 
always 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 lower part of each table gives the kinds and amounts of 
the different feeding stuffs eaten per day, and the weights of 
the digestible nutrients (protein, fat and carbohydrates) which 
they furnished. ‘These weights are given per 1,000 pounds 
live weight and also per average weight of each herd. This 
last is the weights actually fed in each case, and they are given 
in the last five columns of the table. 
As stated above, all of the different feeding stuffs used in 
these rations were analyzed. From the weights of the dif- 
ferent feeding stuffs the results of the analyses and the diges- 
tion coefficients given in the following table, the weights of 
digestible nutrients were calculated in the usual way. The 
fuel value or potential energy furnished by the different foods 
was obtained by multiplying the number of pounds of protein 
and of carbohydrates by 1860, and the number of pounds of fat 
by 4220, and taking the sum of these three products as the 
number of calories of potential energy in the materials. 
