'"the Journal of Heredity 



JOHANNA DE KOL CONCORDIA 



FIGURE 11. At three and a half years of age her record was 19037 pounds of milk and 671 

 pounds of butterfat. Her sire, Sir Clothilde Concordia, was two years nine months of age when 

 she was born, while her dam, Cold Spring Johanna De Kol 2nd, was three years and a half old. 

 The great number of cases where the parents of high producing cows are as young, or younger 

 than these, leaves no doubt that the off-spring of immature parents are just as good producers or 

 transmitters of production as those born when the same parents are mature. Photo by U. S. 

 Department of Agriculture. (See text, p. 173.) 



In practical breeding, it would be 

 very advantageous to know definitely 

 whether the young born of immature 

 parents are as valuable for production, 

 and for reproducing their kind, as 

 those born of more mature parents. 

 It is the aim of this paper to show 

 whether the parentage of a group of 

 high producing or superior cows aver- 

 ages older than the parentage of a group 

 of comparatively low producing or 

 inferior cows. The paper also attempts 

 to show the percentage distribution of 

 offspring for the various ages of both 

 sire and dam; the age when cows 

 actually make their best records; and 

 whether the offspring of very young or 

 very old animals are inferior. 



METHOD 



The data reported in this paper were 

 taken from Volume 27 of the Ad- 

 vanced Registry Year book and the 

 Herd Books of the Holstein Friesian 

 Association of America. 



The superior class of animals chosen 

 include those that up to April 30th, 

 1916, had made records of 24 pounds 

 or more of butterfat in seven days. 

 This included all of the so-called 

 thirty pound cows since 24 pounds of 

 butterfat is equal to 30 pounds of 

 eighty percent butter. For purposes 

 of more careful study, this class was 

 divided into three groups as follows: 



Group I All cows producing over 

 27.3 pounds of butterfat in 7 days. 



