266 Maine Agricultural Experiment Station. 1919. 



The populations of the daughters' milk production and 

 butter-fat percentage were divided into four equal divisions as 

 to numbers contained therein. The same was done for the 

 dam's population of milk production and butter-fat percentage. 

 These parts were designated A the highest milk production or 

 butter-fat percentage as the case may be, B the next highest, C 

 the next lowest, and D the lowest. The relative milk produc- 

 tion or butter-fat percentage of each daughter-dam pair has 

 been determined in this manner. The position of the dam is 

 placed first and the position of the daughter second. Thus a 

 record AB for milk production states that the dam's milk pro- 

 duction was above 10403 pounds and the daughter's milk pro- 

 duction between 9312 and 10780 pounds. 



With these preliminary facts in mind the data may be giv- 

 en on the individual transmitting power of the sires. There 

 are 224 Jersey Registry of Merit sires which meet the require- 

 ments of this performance test for their transmitting qualities 

 in milk production. One hundred and five of these sires or 

 less than one-half raise the milk production of their daughters 

 over that of the dams of these daughters. The largest number 

 of daughter-dam pairs is 39 for the sire Hood Farm Pogis 9th, 

 5555 2 - Of those sires which have a large number of pairs 

 Hood Farm Torono, 60326 with 34 pairs stands first in his 

 transmitting qualities raising the milk production of his daugh- 

 ters on the average 26201 pounds. The relative milk produc- 

 tions of his daughter-dam pairs on a percentage basis are 26 

 AA— 3 AB —9 BA —3 BC —32 CA —9 CB —9 DA —3 DB 

 — 3 DC. Described in words, this bull was bred to 26 per cent 

 of the highest group of milking cows and produced 26 per cent 

 of the highest group of milk daughters ; bred to 3 per cent of 

 the highest group of milking cows he produced 3 per cent of 

 the second highest group of daughters, etc. 



The next sire with a good number of daughters was Sperm- 

 field Owl. This bull with 26 daughter-dam pairs raised the 

 milk production of these daughters on the average 1695.7 

 pounds. The relative milk productions of his daughter-dam 

 pairs on a percentage basis are 12 A A — 4 AB-(-4 AC+23 BA 

 -f 12 BB+4 BC+8 CA+8 CB+4 CD+12 DA+4 DB+8 DD. 



Among the other sires standing well up in the lists might 

 be mentioned Queen's Raleigh, 88232; Sans Aloi 81012; Ter- 



