268 Maine Agricultural Experiment Station. 1919. 



ter of 1 2 1. 5 1 pounds. The next bull, Spermfield Owl, with 26 

 pairs raised the butter-fat production 97.71 pounds on the 

 average for each of his daughters. Some of the bulls lowering 

 the production of their daughters markly were Gertie's Son 

 of Washington 83799, Hood Farm S. Tormentor 9631 1, and 

 Oxford Lad's Owl 75599. 



The information summarized above was arranged to re- 

 veal the transmitting qualities for milk production, butter-fat 

 percentage and butter-fat of Jersey sires to their sons. There 

 were in this table 159 sires which had sons whose progeny per- 

 formance was known. Of this number 69 or significantly less 

 than half had sons who raised the butter-fat production of their 

 daughters over that of their dams. Among these sires who 

 had sons of merit Signal's Crown Prince 61621 and Chief En- 

 gineer 47148 are the leaders. Among those sires whose sons 

 lowered the butter-fat productions of their daughters may be 

 mentioned Merry Maiden's Grandson 91003 and Ethleel 2d's 

 Jubilee 18249. 



The sires of superior merit are defined as those which raise 

 the milk production and butter-fat percentage of their daughters 

 as compared with that of their dams. The inferior sires are 

 defined as those sires who lower the milk production and but- 

 ter-fat percentage of their daughters as compared with the 

 same variables in their dams. The superior sires so defined 

 are arranged by the amount of butter- fat that they increase the 

 production of their daughters over that of their dams. The 

 inferior sires are classified according to the amount of butter- 

 fat that they decrease the production of their daughters in 

 comparison with that of their dams. These two groups of 

 sires are subjected to four generation pedigree analysis to de- 

 termine their inbreeding and relationship, the amount of Island 

 and American stock, "males and females" and "on the sire's 

 side of the pedigree and on the dam's side of the pedigree," 

 and the individual animals most frequently repeated in the two 

 groups of pedigrees. 



There are 28 sires in the group of sires superior in their 

 transmitting qualities for milk production and butter- fat per- 

 centage. In the group of sires inferior in their transmitting 

 ability for these two characters there are 47 sires, a ratio of. 1 

 to 1.7. Such a difference speaks for itself. It emphasizes with 



