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The Cornell Reading-Courses 



Colostrum is not considered fit for human consumption. Previous to 

 the secretion of colostrum the udder has usually been in a state of inac- 

 tivity, and just before or just after the birth of the calf it suddenly becomes 

 very active. This sudden activity may result in more or less inflam- 

 mation; and whenever there are inflammatory conditions, poisons that 

 may be harmful to the human system are likely to be given off. The 

 New York State dairy laws regard colostrum as one form of adulterated 

 milk, and prohibit the sale of milk from a cow either fifteen days before or 

 five days after calving. 



By referring to the above table showing the composition of colostrum, 

 it will be noted that there is a high percentage of albumen. Since heat 

 readily coagulates albumen, boiling the milk is used as a test to determine 

 when it has passed from the colostrum to the normal stage. Because of its 

 high albumen content, colostrum thickens at once when boiled. Normal 

 milk does not thicken when boiled. 



CONSTITUENTS OF MILK 



Milk fat 



Fat is one of the most important constituents of milk. As a food milk 

 is better if it contains a fair percentage of fat than if this percentage is 

 small. For manufacturing purposes, milk fat is very important. One of 





Cream Milk Skimmed milk 



FlG. 26. — The appearance of cream, milk, and skimmed milk when examined through 

 a high-power microscope. The round bodies are fat globules that float in the serum, 

 or watery part of the milk 



the best illustrations of this is in the manufacture of butter, which is 

 largely fat. Also, more cheese can be made from one hundred pounds of 

 milk rich in fat than from the same quantity of milk with low fat content. 

 The amount of fat in milk is so important that milk is frequently bought 

 on the fat basis. The percentage of fat in milk is usually determined by 

 the Babcock test. 



