120 



Maine Agricultural Experiment Station. 1919. 



There are in this list 225 bulls which have two or more 

 daughters from tested dams. Of these bulls 101 raised the 

 butter- f?.t percentage of their daughters over that of their 

 dams. The number of bulls which improved the Jersey breed 

 were somewhat less than half of those in use. In this list the 

 greatest number of daughter-dam pairs for any given bull is 

 42 for Hood Farm Stoke Pogis 9th. A close second to him is 

 Hood Farm Torono with 41 pairs. 



The bull which caused his daughters to have the highest 

 butter-fat percentage over that of the butter-fat percentage of 

 their dams, was the bull Clear Brook Chief (1). This bull 

 raised the butter-fat test of his daughters 1.338 per cent of 

 butter-fat from class D dams he raised his daughters to class 

 A. In this case there were only 2 daughter-dam pairs to base 

 this judgment as to the bull's worth, but even so, the probable 

 errors shown in table 3 indicate that in this case the rise is 

 probably significant in the statistical sense. 



Of the bulls with a larger number of daughters Irene's 

 King Pogis is the leader raising the production of his daugh- 

 ters' (0.650) per cent butter-fat over that of their dams'. 



It is of interest to take the lists of leading native and im- 

 ported sires for illustration of the use of this table as was done 

 for the table showing the transmitting qualities of Jersey sires 

 for milk production. The sires are listed below in the two groups. 

 Their number in table 5 and the amount of butter-fat percent- 

 age by which they raised and lowered the butter-fat percentage 

 of their daughters over that of their dams immediately follows 

 their name. 



The leading native bulls are, omitting those which have not 

 at least two daughter-dam pairs : 



Hood Farm Pogis 9th 



(50) 



+0.243 



Significant 



Hood Farm Torono 



(142) 



—0.225 



Probably significant 



Spermfield Owl 



(98) 



+0.027 



Not significant 



Loretta's King 



(178) 



—0.430 



Significant 



Sayda's Heir 3d 



(65) 



+0.166 



Not significant 



Hector Marigold 



(9) 



+0.617 



Probably not significant 



Irene's King Pogis 



(8) 



+0.650 



Significant 



Lady Letty's Victor 



(77) 



+0.134 



Not significant 



