CHAPTER VIII 

 THE DAIRY COW 



The dairy cow is an animal machine for making milk. This 

 machine takes in feeds like hay, grass, and grain. From 

 these she extracts the nutrients, protein, carbohydrates, and 

 fat or ether extract, and also some mineral matter and water. 

 Mineral matter and water are also taken in other forms than reg- 

 ular feeds. All of these materials, and perhaps some others 

 which have thus far avoided detection, but are a part of the 

 feeds eaten, are taken to the living cells of the animal body 

 where they are put together in the form of milk. Thus, milk- 

 making is a function of the living animal cell. Manufacturers 

 have thus far not succeeded in making milk by artificial means. 



Milk. — Milk is a combination of water, fat, casein, albumin 

 and salts. It contains as a rule from 3 to 7 per cent, of fat. 

 The amount of protein as a rule (casein and albumin) is a 

 little smaller than the amount of fat present. Where milk 

 is run through a separator or is skimmed the fat and some of 

 the milk serum are taken away from the rest of the serum. 

 Thus, cream contains 25 per cent, of fat, more or less according 

 to the gauging of the machine. 



Butter. — Butter is the fat of the milk with a little salt and 

 water in it. To make butter the cream is allowed to ripen 

 or to sour a little. This forms an acid which acts upon the 

 casein in the milk serum in such manner as to free the fat 

 globules to some extent. The ripened cream is put into a 

 churn and tumbled around to make the fat globules come into 

 contact with one another and stick together. When enough 

 stick together, the mass separates from the milk serum. The 

 latter is then known as butter milk. Thus, butter forms like rain . 

 When it rains the fine dew drops come together to form rain 

 drops. When butter is made the fine fat globules of the milk 

 or cream are pounded together into larger grains and then 

 there is butter. 



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