FIFTY-THIRD ANNUAL CONVENTION 97 



their records have been compared with the records of their 

 dams. 



Such comparison of records, of course, can not be 

 made until some of the daughters are old enough to have 

 completed or nearly completed their first lactation periods. 

 Because of this delay, cow-testing-association records of the 

 dams and daughters in bull-association herds have become 

 available slowly. So far, however, they have shown that 

 the bull association has been successful in its main purpose, 

 the building up of better herds of dairy cattle. 



There are 155 yearly production records of the daugh- 

 ters of bull-association bulls now available from 12 States. 

 These have been compared with the yearly records of the 

 dams of the daughters. These are not the records of selected 

 daughters but of all those that have been tested and whose 

 records have been compared with the records of the dams. 

 On the average the dams produced 7,112 pounds of milk 

 and 299 pounds of butterfat a year, and the daughters 

 8,071 pounds of milk and 342 pounds of butterfat. On an 

 average the daughters excelled their dams 13.5 per cent 

 in milk production and 14.4 per cent in butterfat. 



These percentage gains would not mean much if the 

 dams were low producers, but it requires a bull much 

 above the average purebred bull to raise the production of 

 his daughters above that of dams that produce each year 

 approximately 7,000 pounds of milk and 300 pounds of 

 butterfat. In order to make a fair comparison between the 

 records of immature and mature cows the records of all 

 immature cows are figured to maturity. For cows 2, 3 and 

 4 years of age, this is done by multiplying the records made 

 at these ages by 100 and dividing the result by 70, 80 and 

 90, respectively. 



Some of the sires were very outstanding. One was 

 mated with dams having an average yearly milk production 

 of 9,300 pounds and an average yearly butterfat production 

 of 347 pounds. The seven daughters of this bull produced 

 57 per cent more milk and 44 per cent more butterfat than 

 the average of their dams. More remarkable still, every 

 daughter excelled her dam. 



