Holstein-Frieaiana 149 



numbers, as these cows did in the years im- 

 mediately following their importation, a theo- 

 retical table shows that 28.6 per cent, of all 

 births are first calves, 20.9 per cent, are sec- 

 ond calves, 15.8 per cent, are third calves, 1 1 .5 

 per cent, are fourth calves, and the remainder 

 are fifth and later calves. A tabulation, 

 however, shows that the deaths of older cows 

 slightly increases the percentage of earlier 

 births and decreases the percentage of later 

 ones. This tabulation gives 51 percent, of 

 first and second calves, 25 per cent, of third 

 and fourth calves, and 24 per cent, of fifth and 

 later calves. 



On this basis, 510 of the 1000 dams in these 

 pedigrees should have been with either their 

 first or second calves, and 240 should have been 

 with their fifth or later calves, provided, of 

 course, that the dynamic development a cow 

 acquires by producing milk is not transmitted 

 to her later offspring. Asa matter of fact these 

 pedigrees showed no such number of first and 

 second calves. They showed that 238 first 

 and second calves had been eliminated, and 



