92 Milk and Its Products. 



organs regain their tone. Disorders of this sort 

 are especially likel}' to occur when cows that have 

 been poorly- fed during the winter are suddenly turned 

 on fresh rank pasture in the spring. 



Quality of milk for consimii)tion. — The fat is the 

 most variable and the most valuable constituent of 

 the milk, so that milk is ordinarily considered to be 

 of value for human food in proportion to the amount 

 of fat it contains, but where it is to be used as 

 a food in large quantities, the fat may frequently 

 be present in too large quantities for the digestion 

 of many persons. Milk containing about 4 per 

 cent of fat is probably an ideal food for the gen- 

 eral mass of human beings. If there is above 5 

 per cent of fat the other solids are somewhat out 

 of proportion, and many are likely to have trouble 

 with their digestion from using large amounts of 

 such milk. On the other hand, if there is less 

 than 3 per cent of fat, the casein and other solids 

 are in too great proportion to the fat, and are less 

 readily digested. The question of the healthfulness 

 of milk from which a large part of the fat has been 

 removed is one frequently discussed. The removal of 

 the fat does not thereby in any way injure the other 

 solids ; they are still there, and still as useful for 

 food as before the fat was removed, only in con- 

 suming such milk as food the fat must be supplied 

 in some other way. For the person of vigorous 

 digestion, who for reasons of economy desires to 

 supply the fat required by his system in some 

 cheaper form than that of milk fat, skimmed milk is 



