THE GENERAL COMPOSITION OF MILK 



2T 



The increase in the amount of milk produced may evidently 

 cease to be profitable to the farmer, owing to the greater cost of 

 the food required to produce it. 



Koning found that poor food caused a fall in the fat-content and 

 in the 'solids not fat.' The addition of even 200 gms. of sodium 

 chloride to the food gave no increase of chlorides in the milk. 



Kohn showed that a somewhat higher fat-content was obtained 

 when goats were partly fed on the meadows, instead of with dried 

 food only. The ash also rose somewhat with meadow feeding. 



Engel and Plaut found that the milk of a nursing woman is 

 reduced if there is insufficient fat in the diet, but that increasing 

 the fat in the food did not increase the fat in the milk. 



Allemann endeavoured to alter the composition of the milk 

 by alteration in the food given, but without success. The addition 

 of large quantities of salt to the food was not successful in causing a 

 rise of salt-content in the milk. When, however, saltpetre was used 

 in large quantities, traces of this could be detected in the milk. The 

 fact that traces of the abnormal salt were found in the milk is of 

 interest in connection with the work of Engel and Murschhauser. 1 



When certain important constituents of the food fall below 

 the physiological limit, the amount of milk secreted is reduced. 

 This would appear to be due to a physiological mechanism, designed 

 to prevent undue depletion of the organism. 



'Thus Fingerling found that when goats were fed on a diet 

 poor in calcium and phosphorus, a fall both in the amount of the 

 constituents and of the total milk occurred. This drop commenced 

 when a certain degree of depletion had been reached consequent 

 on the reduction in intake of these constituents. On restoring the 

 calcium and phosphorus the secretion returned to normal. 



Cathcart and Paton, in the course of experiments undertaken to 

 determine the source of lactose in milk, fed a goat on a diet calcu- 

 lated to reduce the carbohydrate taken, and administered phloridzin 

 to remove the store of glycogen. The amount of milk given fell 

 very rapidly also the ash-content but in two instances the fat- 

 content rose. At one period the secretion of milk almost stopped. 



1 See p. 42, 



