Structured Sire Evaluation

History of Program

The first Structured Sire Evaluation Program was specifically designed to develop growth-trait expected progeny differences (EPDs). A part of the National Sire Evaluation program, a new carcass evaluation program was adopted in 1972 that resulted in the first Angus Sire Evaluation Report and formed the foundation of the Angus performance records database.

Reestablished in the fall of 2015, the current Association-sponsored Structured Sire Evaluation has a different purpose than its predecessor. The current program aims to collect carcass data on widely used bulls in the Angus population that have little to no actual carcass data collected on their progeny. These widely used sires have ultrasound records on progeny but no true carcass records. The ability to use ultrasound data to predict carcass traits is a very powerful and useful technology, but since it is not a perfect correlation of 1, actual carcass records are still needed for more accurate predictions.

Current Program

Widely used bulls are those included in the Top 300 Registration Sires the previous fiscal year, and in most cases are proven for growth traits and may even have hundreds of progeny ultrasound records reported. Targeted commercial participants then choose which bulls they would like to use in their operation, breed the females, and are provided compensation once carcass data records are submitted. The data from this program enters the weekly evaluation in the same way as every other data point — subject to contemporary group guidelines — and supports the evaluation in the same capacity. Ultimately, it increases the accuracies on widely used sires, which improves prediction accuracies of genomic evaluations, adds phenotypic data to the robust Angus database, and provides an opportunity to validate selection tools. Sires used in this program consist of both test and reference sires.

Nomination of Test Sires

In January of 2022, the program grew to including sires nominated by Angus members. This allows Angus members to nominate unproven sires to be used in the program. Nominated sires selected by test herds to be used will have the opportunity to obtain carcass data on progeny compared to proven, high-accuracy Angus sires, improving accuracies on carcass traits. Nominations for sires are due by January 15 each year. To nominate a sire(s), fill out and submit the nomination form.

Benefits of the Program
  • Obtaining high accuracy Expected Progeny Differences (EPDs) for carcass traits
  • Collecting performance data on progeny
  • Verify an unproven sire alongside proven, high accuracy Angus sires
  • Further link actual phenotypes to genomic information to continuously increase genomic prediction accuracy
  • Allow for continued validation of the Angus’s national cattle evaluation through collection of performance data on progeny
Responsibilities of Bull Owner/Nominator
  • Complete nomination form and initial fee for test sire(s) by January 15
  • Pay nomination fee for test sire
  • Provide 100 units of viable semen and pay shipping costs
Requirements for Nominated Sire
  • Registered Angus Bull
  • Must meet current requirements for “Out of Herd” AI Sires including
    • Parentage markers on file with the Association
    • Genetic condition bundle testing
  • Genomically tested with AngusGS℠ or HD50K for Angus
  • Viable semen collected and froze
  • Be able to provide photo and video of sire upon request
Responsibilities of Test Herds
  • Select the sires to use from list provided by the Association
  • Randomly mate females to sires selected
  • Dams in project must be permanently identified, provide birth year, and approximate breed composition
  • Record submission including breeding, calf ID, birth date, weaning weight, EID identification, DNA sample with testing materials provided, weaning weights, management group information, and carcass data
  • Collect DNA samples on calves for sire verification
  • Maintain complete or partial ownership of fed cattle to access carcass data
  • Provide carcass data including a minimum of harvest date, hot carcass weight, backfat, ribeye area, and marbling score
Responsibilities of American Angus Association
  • Communication between test herd and nominator
  • Coordinate semen shipments to test herds
  • Supply reference sire semen to test herds
  • Ensure data and DNA sample submission
  • Collect DNA samples on calves for sire verification
  • Provide EID tags, TSU units for testing, and cover cost of genotyping
  • Receive data and report results back to bull owner and test herd

For more information on the Structured Sire Evaluation, contact the Performance Programs department at 816-383-5100 or email

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