Keep an Eye on Where Your Service Sires Rank

Dairy Pipeline: October 1998

Bennet Cassell
Extension Dairy Scientist, Genetics and Management
Virginia Tech
540-231-4762
bcassell@vt.edu

Did you use a good service sire the last time you bred a cow or heifer on your farm? It's easy to say "I always use good bulls" but the real test is whether you could have realistically used a better bull than the one you used. The objective way to make that comparison is to know where service sires rank on the index you use to select service sires. Below is a table of Net Merit values for active AI bulls from the August genetic evaluations for three dairy breeds. Net Merit is a very useful index for commercial producers because of its emphasis on high productivity as well as longevity. If your last service sire was a Holstein bull with a Net Merit rating of over $193, he was in the top 10% of all active AI Holsteins available. It would be hard to make a "better" decision. On the other hand, if his Net Merit rating was $150, then about half the active AI Holsteins on the market would be a "better" choice! Make the best use of each opportunity offered by an AI service by using high ranking bulls as much as you can.