THE FEEDING OF MILCH CATTLE 321 



The daily average of milk per head in the last 

 twenty days of each period was (in kilograms) : — 



Groups. 



A. E. C. 



1st period . . 13-80 13-80 13-80 

 2nd or maize period 1175 11*85 l*"55 

 3rd period . . 10-65 10-65 I( >65 



The analysis of the milk for its percentage com- 

 position showed there was no difference at any time 

 between the three groups. Naturally in these 

 investigations, whether they be carried out accord- 

 ing to one or the other method, the other properties 

 of the milk (smell, taste, churning properties, 

 nature of butter) must be noticed, and the live 

 weight of the- animal regularly recorded. 



(5) The effect of food on the milk production. 



(a) General considerations. 



As milk is practically only changed mammary 

 gland substance, it depends largely upon the develop- 

 ment and activity of this gland what proportion of 

 the nutrients flowing to it are converted into milk. 

 There is, however, a limit to the development of 

 the mammary gland as there is to all other organs, 

 and adaptation and heredity determine this : The 

 individuality and breed of the animal and the condi- 

 tion of the mammary gland, as influenced by the 



Y 



