146 Animal Husbandry 
There are three ways in which the composition might be affected: 
first, by changing the proportion of water and total solid matter ; 
second, by changing the proportion of fat, sugar, and proteids ; 
and third, by changing the constituents or consistency of the fat. 
239. Effect of food on total solids. — In the great majority of 
cases the conclusion of experiments is that no consistent relation 
seems to exist between the quantity or character of the food and 
the composition of the milk. In a few cases a temporary change 
occurred in the milk immediately 
after changing the food, but in 
most cases the milk soon returned 
to its normal composition. While 
in a very small number of experi- 
ments the milk appeared to un- 
dergo slight permanent change, yet 
one is forced to the conclusion that 
the quality of the milk cannot be 
changed at will by the feed. The treatment of the cattle has 
a greater influence upon the character of the milk than does the 
food consumed. 
240. Effect of food on the percentage of fat. — The idea prevails 
that it is possible to feed fat into milk. After a painstaking perusal 
of the experimental work, one is forced to conclude that it is 
not possible materially and permanently to increase or diminish 
the percentage of fat by changes in the amount and character of 
the food, providing, of course, that the animals receive sufficient 
nutrition in all cases. A cow that has been insufficiently fed and 
has never had a chance to develop, may be fed such an abundance 
of rich milk-producing food as slightly and permanently to in- 
crease the percentage of fat in her milk; but beyond this we prob- 
ably cannot go. 
241. Food and flavor of milk. — It is definitely known that cer- 
tain foods, especially if fed in large quantities, impart bad odors to 
the milk. Chief among the foods producing such deleterious effects 
Fig. 62.— Holstein-Friesian cow. 
