14S Dynamic Evolution 



of three generations of old dams in this 

 country. To learn what effect one year more 

 or less from time of importation to time of 

 investigation would have on the age of dams, 

 the cows selected were divided into groups, 

 one group consisting of cows born in 1901, a 

 second group consisting of cows born in 1902, 

 and a third group consisting of cows born in 

 1903. The results will be given later. 



The time of importation limited these pedi- 

 grees to three generations, and even some of 

 these were fragmentary. All of the cows 

 which were born in the years indicated and 

 which were officially tested up to February 

 !5> J 907. were gone over in detail and from 

 them were picked out 144 which produced 

 more pounds of milk in seven days than any 

 others recorded. A stop was made at this 

 point because these cows had in their pedi- 

 grees just 1000 dams. 



Holstein-Friesian cows usually first come 

 fresh at the age of two years, and then regu- 

 larly each year thereafter. When cows are 

 bred in this way and increase normally in 



