Date of this Version
Daughter superiorities of 240 Holstein bulls of the American Breeders Service and Eastern Artificial Insemination Cooperative (EAIC) were estimated from records of paternal sisters of the sire, dam's records, and records of daughters of the maternal grandsire. Estimated daughter superiority (EDS) was then compared with the U.S. Department of Agriculture's predicted difference for American Breeders Service bulls and with the Northeast Sire Comparison for EAIC bulls. The regression equation on estimated daughter superiority was [-84 + .561(EDS)] kg for American Breeders Service bulls and [-227 + .654(EDS)] kg for EAIC bulls. The response is not as large as theoretically predicted but does indicate that selection of young bulls with high estimated daughter superiority is an effective method of finding a superior group of young bulls for further sampling.