MILK AND ITS HYGIENIC RELATIONS 



in the case of human milk. It is not unlikely that the explana- 

 tion of this apparent divergence may be found in the fact that 



Diagram showing Variation in Yield and Composition of Milk from One Cow, 

 the estimations shown representing th^average on each ^-weekly period. j* 



Periods 



567 



10 n 



Fat, average 2-93 per cent. 



Total Protein, average 2-68 per cent. 



. . Casein, average 2-11 per cent. 

 Sugar, average 4-26 per cent. 



The milk yield in pounds is shown by the plain line falling gradually 

 throughout the period of lactation. 



The curves showing the changes in composition are arranged to show the 

 percentage rise or fall above the average percentage for each constituent, 

 which is represented by the zero line. 



* t 



these cows were all pregnant in the later months of lactation. 

 Samples taken from five cows who were farrow showed little 

 alteration in the constituents of the milk taken at the same 



