IGS Updates Docility Evaluation – Changes affect EPDs released week of April 13

Over the past several months the IGS team has been working to harmonize methodology implemented across the various trait suites in the current IGS production runs.  The principle change to Docility was a change in contemporary group structure. Previously, docility records observed at weaning or yearling had to have the same observation date and the animal’s weight trait record. Animal records not conforming to this requirement were removed from the evaluation. Under the new evaluation structure, weaning and yearling docility observation date are added to the contemporary group definition. Across the evaluation, this will result in approximately 6% more records being pulled into the production run. The evaluation is a single-trait model that utilizes genomic and external EPD information in addition to pedigree and docility phenotypes. The evaluation has some flexibility in data reporting. Producers may submit weaning and/or yearling docility observations. If both are on file the weaning record is used as it is typically from a larger contemporary group.

The other modifications mirror changes to weight traits, carcass and calving ease evaluations . In the docility run the primary change is updating the handling of the breed by decade interaction which is now decoupled providing better stability of solutions. Additionally, the new structure includes all genotyped animals in the evaluation so they have genomic solutions for the formation of the EPD. External EPD information incorporation was modified to align with methods used in the other traits suites. Collectively, these changes resulted in very, very small changes in rank correlations of animals between the new procedures and previous strategy was >0.99, meaning most animals are essentially unaffected by the update.  Animals whose record is now included in the run, or parents with new progeny records included are expected to have movement in their EPDs.