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. 



B. 



ist period . . 13-80 13-80 13-80 

 2nd or maize period 11-75 11-85 IX '55 

 3rd period . . 10-65 10-65 io >6 5 



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 



