

R ahh 
118 REPORT OF THE DIRECTOR OF THE 
With a view to the further elucidation of this question, the ~ 
following table presents the results obtained from each (of the 
animals under investigation during the entire period of lactation 
of most of them, and the relation between certain constituents of 
their food and certain of the milk constituents. 
It will be seen that the amount of albuminoids present in the 
food was 264 per cent greater than the caseine of the milk, a 
result which closely agrees with previous results secured at the 
Station, since, as the average of these results, we find that 27.5 
per cent of the albuminoids of the food were utilized in milk pro- 
duction, while, in a previous experiment with five cows, it was 
found that the caseine of the milk produced by them was equal to 
26.5 per cent of the albuminoids present in the food consumed 
by them. 
It will be seen that the excess of albuminoids consumed over 
and above the caseine found in the milk was almost exactly 
double (198 per cent) the amount of the fat produced in the milk; 
also that the crude fat (ether extract) present in the food was 17 
per cent greater than the fat present in the milk. 
» It is obviously of very great practical importance to determine , 
if possible the source of the fat present in the milk, and the data 
already presented is valuable as throwing some light upon this as 
yet unsettled problem. 
Dr. Foster, the eminent physiologist of Cambridge, England, in 
the latest edition of his Physiology, says, on page 785, that “the 
quantity of fat present in milk is largely and directly increased 
by proteid, but not increased, on the contrary diminished, by 
fatty food”; and upon page 773 he quotes approvingly that 
“Liebig showed that the butter (fat?) present in the milk of a 
cow was much greater than could be accounted for by the scanty 
fat present in the grass or other fodder she consumed.” 
Now we have shown in the table, page 115, that the average of 
thirteen cows gave a consumption of 62.3 pounds of albuminoids 
and of 26.4 pounds of crude fat, with a production in the milk of 
19.6 pounds of fat, during the month of August; while in Septem- 
ber they consumed upon an average 78.9 pounds of albuminoids 
and 22.3 pounds of crude fat, with a production of but 17.3 pounds 
of milk fat; or an increase of 15.5 per cent in the fats consumed 

