Last updated February 4, 2008 - Chad Dechow, Editor
Copyright ©2008 Penn State University
Breeding Performance Summary
The Sire-Son and Prefix reports were developed at Penn State University by Dr. Larry Specht and first published in the mid 1970s. The reports have been used to compare the performance of a sire with his sons and provide a list of the prefixes that are providing the top Holstein bulls to the A.I. industry in the US. The Bull-Mother report is a spin-off from the original Sire-Son and Prefix reports and lists dams that have provided the top Holstein bulls.
View the Reports:
- Sire-Son Report (http://www.das.psu.edu/user/bullrank/sireSon.cfm)
- The top 150 sires sorted by Sons Lifetime Net Merit (Son NM).
- The Prefix Report (http://www.das.psu.edu/user/bullrank/prefixes.cfm)
- The top 150 prefixes sorted by bulls' Lifetime Net Merit.
- The Bull-Mother Report (http://www.das.psu.edu/user/bullrank/bullmothers.cfm)
- The top 100 dams sorted by Sons Lifetime Net Merit (Son NM).
Frequently Asked Questions:
- What bulls, prefixes and cows are included in the reports?
- Sires and Prefixes with at least 20 A.I. sons and cows with a minimum of 10 A.I. sons are included. Only US sons that were born in the last 25 years are used.
- How are the genetic averages calculated?
- PTAs are obtained for all sons. The average PTA of the sons is then calculated for each sire, prefix or cow for several traits.
- How are the bulls, prefixes and cows ranked?
- All the reports are now ranked on Lifetime Net Merit, but can be sorted by a variety of traits.
- Who calculates a son's Predicted Transmitting Ability (or PTA)?
- Official national genetic evaluations are generated by the Animal Improvement Programs Laboratory (http://aipl.arsusda.gov) at the USDA for production traits. Official national genetic evaluations for PTAT are calculated by the Holstein Association USA, Inc (http://www.holsteinusa.com).