For example, the average age of proven bulls when their daughters are born is 7 yrs or more, while the average age of young bulls when their progeny are born is 2-3 yrs. Justification of Young Sire Use The results of a recent study indicate that proper and more extensive utilization of young bulls can be profitable for dairymen. The poorest young sires used in the study were inferior to the poorest proven bulls for both milk and fat yield. This wide range of PDs for the young sires illustrates an important point. If it were, there would be no need to progeny-test the young bulls.
Risk is involved with young-sire use.
To minimize this risk, a group of young bulls should be used in the herd rather than heavy use of 1 or 2 bulls. Daughters of young bulls should perform well as a group, even though two or three bulls will likely be below expectation. It is also important to practice intense pedigree selection. These guidelines should be reduced by about 1000 lbs for Holsteins, the change in genetic base, then PD82 is implemented in January, 1984. Target ETA and PI would then be 700 and 300 lbs of milk.