Composition of Milk and Some of its Products 



1637 



For purposes of convenience the content of milk is grouped in several 



divisions, as represented in the following table: 



Water 

 'Fat 

 Sugar 

 Casein 

 Albumen 

 Ash 



Total solids 



Fat 



Water 



Sugar 



Albumen 



Casein 



Ash 



Whey 



There is a small amount of ash in whey, also, and this is the part that 

 is soluble. 



The density of milk is greater than that of water, the specific gravity 

 of normal milk being 1.029 to 1.034, with an average of 1.032. The specific 

 gravity of milk is affected by variation in the milk solids. The New 

 York State laws require that milk must contain not less than 11.5 per 

 cent of total solids, of which at least 3 per cent shall be fat. 



One quart of milk weighs 2.15 pounds. While milk is variable in com- 

 position, the variation is not enough to make a great difference in the 

 weight of one quart. This factor, 2.15, is the one used in changing quarts 

 to pounds or pounds to quarts. 



COLOSTRUM 



The milk secreted by the cow a few days before and a few days after 

 the birth of a calf is called colostrum, or beestings. It differs in appear- 

 ance and composition from normal milk and its composition is variable. 

 Usually, colostrum is low in sugar and fat, and high in albumen and ash. 

 The following table, taken from Fleischman, gives the average composition 

 and the maximum and minimum variation of colostrum: 



It is highly desirable that the young calf receive the colostrum, for this 

 food acts as a purgative and a stimulant to the digestive system of the 

 young animal. 

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