MILK AND ITS PRODUCTS 



173 



ceni and sufficient sugar, usually milk sugar, to raise the 

 consent of this constituent to that found in human milk. 



A knowledge of the composition of milk produced by 

 the common domestic animals will be found of value at 

 tim< s. For example, if it becomes necessary to raise a colt 

 by 1 and, a study of the table giving the composition of mare's 

 mill, will show clearly that even average cow's milk should 

 be diluted with water before being used for this purpose. 

 Cane sugar is often added. 



T!ie exceedingly rapid growth of small animals is ex- 

 plained by the very rich milk that small species always 

 produce. As a general rule the larger the species, the slower 

 the growth of the young, and the smaller the amount of solids 

 in tl ie milk. Animals living in arctic regions or in the ocean 

 are exceptions. These conditions require a large amount of 

 fat for fuel to keep the young animal warm. This interesting 

 fact is illustrated by the composition of the reindeer's milk 

 and also by that of certain marine animals such as the walrus 

 and the porpoise which secrete the richest milk known. 



161. Breed. The milk from different breeds of cows 

 differs in composition. Table 20 gives a summary of all 

 the published records of American Experiment Stations on 

 this subject up to 1913 : 



TABLE 20. COMPOSITION OF MILK BY BREEDS l 



U. S. Dept. Agr., Bureau of Animal Industry, Bulletin 156. 



