CHAPTER VI 

 MARKET MILK 



THE production of milk for direct consumption is one of the 

 important branches of the dairy industry, and becomes in- 

 creasingly so with the continued rapid growth of the cities. 

 The ideal milk supply is the one which reaches the consumer in 

 the condition in which it leaves the udder of the healthy cow. 

 Where milk is consumed at the place of production, such a 

 supply is possible because the conditions of production are 

 known and the milk is consumed while fresh, but in the case 

 of the general milk business, such a supply is impossible, for 

 the consumer has no control over the conditions of production 

 and does not receive the milk until it is many hours old. Sev- 

 eral things are important in the quality of milk and cream for 

 direct consumption. 



1. Chemical composition. 



2. Freedom from disease-producing microorganisms. 



3. Freedom from bacterial decomposition products. 



4. Cleanliness, including both dirt and bacteria. 



The nutritive value of milk depends primarily on the amount 

 of fat and solids it contains. (See Fig. 39.) Since the relation 

 between the fat and the other solids is fairly constant, and since 

 the total solids vary almost directly with the percentage of fat, 

 the nutritive value of milk and cream is usually considered to 

 be in proportion to the percentage of fat contained. If the per- 

 centage of fat is abnormally high or low, the normal ratio of 

 fat to other solids will be out of balance, but within normal 



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