786 
Journal of Agricultural Research 
Vol. XXXI, No. 8 
experiment than that of the cows in the nonmineral group. This can 
be ascribed in part to the slightly lower ratio of Holsteins to Jerseys 
in the mineral group, but computation shows that this is only a minor 
factor, and the lower yield must be considered as due chiefly to differ¬ 
ences in the inherent ability of the individual cows to produce milk. 
H 
Average for Year 23.13 lie , 23.00 Ihs 
Fig. 1.—ChartjS showing fluctuation in the average daily milk yield per cow—for the station 
herd as a whole, for the group which was fed mineral supplement, and for the group which did 
not receive mineral supplement 
Composition of the Milk 
As already noted, five-day composite samples of each cow’s milk 
have been taken during each month she has been in milk. Total 
solids and fat have been determined regularly on these samples. 
The total ash of the samples has been determined in 12 different 
months extending over a period from June, 1922, to March, 1924, 
The calcium ana phosphorus of the ash have been determined in 
nine different months extending over a period from October, 1922, 
to March, 1924. The results are presented in Table V. 
