140 Maine Agricultural Experiment Station. 1919. 



99th of Hood Farm, and Hood Farm Pogis 9th, the order in 

 which the bulls are named representing in some degree at least 

 the relative worth of the bulls. 



Examination of the sires in table 8 in connection with the 

 list of the worth of these same sires' sons as given in table 7 

 is of especial interest as showing a bull's transmitting powers 

 to both his male and female offspring. The test of these sons 

 is of course one generation removed from the test of a bull 

 himself and consequently is not a test of more than half of the 

 inheritable factors which he may transmit to these sons since 

 the mother transmits the other half. A diagram, purposely made 

 simple, will make this clear. 



Sire bred 



to cows. ... -{ 

 Produces 



^Sons . 



Daughters . 7 



Sons bred 

 to cows~-> 

 Produce 



Sons 



Daughters which may 

 be ;^77 or 7?Tr 



The sire's sons when tested for their merit as shown in the 

 diagram above are also tested for the merit of their dams since 

 the dam of the sons contribute equally with the sire of the sons 

 to the son's daughters. The test of the sire through his sons, 

 consequently, does not have the same value in determining the 

 sire's merit as does the test on his daughters. Taking cogni- 

 zance of this fact we may now proceed to examine these Jersey 

 sires for their merits in transmitting milk production to both 

 their sons and daughters. 



A number of these will not have tested sons. Of those 

 that do have tested sons Spermfield Owl stands first in raising 

 the milk transmitting qualities of his sons. His sons' raised 

 the milk production of their daughters, lowered the butter-fat 

 percentage and raised the butter-fat. A fairly close second to 

 Spermfield Owl was Golden Glow's Chief. This bull's sons 

 also raised the milk production, lowered the butter-fat per- 

 centage and raised the butter- fat of the daughters over that 

 of their dams. 



Among the bulls which lowered the butter- fat production 

 of their sons' daughters Channel King, Mabel's Raleigh, Hood 

 Farm Pogis 9th and Valentine's Oonan may be mentioned. Of 

 the bulls mentioned Hood Farm Pogis 9th lowered the trans- 



