CHAPTER III. 



ABNORMAL MILK. 



ALTHOUGH milk is normally such a desirable and ex- 

 cellent food, it is, like other foods, subject to various 

 modifications and fermentations, depending upon the con- 

 ditions under which it is produced and subsequently 

 handled. This abnormality may be merely a slightly 

 bad odor and flavor or it may be some very marked un- 

 desirable characteristic of color, consistency, odor or taste. 



Again, the milk may appear and taste perfectly normal 

 but at the same time contain pathogenic organisms or 

 toxic properties that may prove serious and even fatal 

 to the consumer. 



Milk may acquire abnormal flavors or odors in several 

 ways: The cow may be slightly sick and produce milk 

 with an unusual flavor. This is usually temporary. 

 Highly flavored foods such as onions or turnips, when 

 eaten by the cow, may impart their flavor to the milk. 

 Milk absorbs any odor that it may be exposed to, such 

 as zenoleum, creolin, or other strong-smelling disinfectants, 

 when used in the barn too close to milking time. Flavor 

 of milk may be altered after it has been drawn, by growth 

 of bacteria in it. The commonest change is the souring and 

 curdling of the milk, due to a fermentation of the milk 

 sugar, in which the latter is broken down into lactic acid. 

 This is a normal fermentation and, though not desired in 

 fresh milk, is not deleterious to health. 



Poisonous Milk. When cows eat leaves of the common 

 poison ivy (Rhus toxicodendron) the toxic properties 



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