COMPOSITION OF MILK 19 



Fat content increases as lactation advances. 



The per cent of fat in milk changes somewhat 

 with the period of lactation. Professor Van 

 Slyke of the Geneva Station, New York, gives a 

 table showing a gradual increase as the period of 

 lactation advances. It will be noticed that for 

 the first five months the milk did not increase in 

 richness, but remained practically the same ; after 

 that the fat of the milk gradually became richer 

 as the period advanced. 



Month of Per Cent of 



Lactation Fat in Milk 



1 4.54 



2 4.33 



3 4.28 



4 4.39 



5 4.38 



6 4.53 



7 4.56 



8 4.66 



9 4.79 



10 5.00 



Influence of time of milking. The time be- 

 tween milkings has a great influence on the fat 

 content of the milk. It is quite generally known 

 that morning milk is richer than evening milk. 

 This is not always true, but in general we find 

 that when a cow is milked three or four times 

 a day she will produce richer milk than when 

 she is milked twice only. As a rule the richer 

 milk follows the shorter period between milkings. 

 This is an important fact to bear in mind when 

 the milk of a cow is tested for its fat content. 



