CHAPTER VIII 



HOLSTEIN-FRIESIANS 



Advanced Registry — Milk Production and Percentage of 

 Fat — Cows Selected — Calves at Different Ages of 

 Cows — Bulls — Time between Successive Births. 



I N 1906 an investigation was made into milk 

 ' production by Holstein-Friesian cows. 

 These cows were selected because their milk 

 production is very great, but as they are 

 classified in the register by the amount of 

 butter fat produced and not by the amount 

 of milk, it was necessary to go through the 

 books in detail to find those which were re- 

 markable for milk production. To explain 

 why this is necessary we must go back to the 

 manner in which energy is acquired by work 

 performed, and to the relationship of this 

 manner to the system used in admitting cows 

 to the Advanced Registry. 

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