90 Maine Agricultural Experiment Station. 1919. 



This measure is clearly a measure of what inheritance for 

 milk production this bull transmitted to his daughters when 

 given, the average inheritance of their dams upon which to 

 work. Such a measure primarily aims at the germ cells, it is 

 in fact, a measure of the genotype of the bull as distinguished 

 from the phenotype. This measure is further entirely free from 

 any preconceived 1 notions of the mode of inheritance of their 

 milk yield. It is entirely free from personal bias. It simply 

 gives in easily appreciated numerical terms what the bull ac- 

 complished, in no way trying to analyze the chain of events 

 which brought about this accomplishment. The measure as 

 applied to the Jersey Registry of Merit Sires (12) is the nu- 

 merical expression of what the breeder means by potency (5). 



Specifically the aims of this investigation will be. 



1. To determine the transmitting qualities of Jersey Reg- 

 istry of Merit Sires, for year milk production. 



2. To determine the transmitting qualities of Jersey Reg- 

 istry of Merit Sires for butter-fat percentage. 



3. To determine the net change in the yearly production 

 of butter-fat between the daughter's production and mother's 

 production for Jersey Registry of Merit Sires. 



4. To determine the transmitting qualities of the Sire's 

 sire as judged by the production of the daughters of his son in 

 comparison with that of their dam. 



5. Pedigree analysis of the superior and inferior sires of 

 the Jersey Breed. 



Material. 



The material used for this study was the records for year 

 test of American Jersey cows contained in volumes I to V of 

 the Jersey Registry of Merit of the American Jersey Cattle 

 Club ( 12). The rules under which these tests are carried on 

 are given in each volume of the Registry of Merit. These rules 

 call for the supervision of each test by an accredited representa- 

 tive of the agricultural experiment station or college of the 

 state under which the test is made. The rules which govern 

 the action of these supervisors are quite inclusive, meeting prac- 

 tically every contingency which might arise in the conduction 

 of the test. The aim of these rules is, of course, the safeguard- 



