|There are a number of major enhancements that have been implemented to the December 2022 TransTasman Angus Cattle Evaluation (TACE). These are outlined below:|
Updated adjustment factors and genetic parameters: A complete re-estimation of genetic parameters for traits reported in TACE was completed this year, with a particular focus on carcase traits. As the current genetic parameters were estimated in 2013, the latest parameter estimates are based on a significant increase in performance records, especially slaughter-endpoint traits and net feed intake. As a consequence, the parameters to be implemented in the December 2022 evaluation will better represent the population of animals with performance records. These updated parameters relate to the main multi-trait analysis only: genetic parameters for calving ease, docility and structural traits have not been updated.
Revised Docility analysis: The current analysis uses animals with a temperament score plus 2 generations of pedigree, which means that many animals do not end up with a Docility EBV. The revised analysis will use the pedigree file from the main multi-trait analysis and the CE analysis, to ensure that all animals in the BREEDPLAN evaluation will have all EBVs potentially available and reported.New accuracy software: The volume of genomic information used in TACE has now reached a point where the algorithm used in the calculation of accuracy has become inefficient in terms of time and memory requirements. A much-improved algorithm has now been developed to more effectively incorporate SNP effects. This represents a major advancement in the analytical software used in TACE and has been scheduled for implementation in December 2022.
Updated parameter files for Index calculation: These are needed to ensure the calculation of indexes reflect the changes in parameters used in calculating EBVs.
Changed approach to using imported EPDs: As of December 2022, EPDs will no longer be updated for American Red Angus animals represented in TACE. Updated EPDs will still be used for Canadian Angus (Black and Red) and American Angus (Black) animals represented in TACE.
Changes in EBVs, accuracy and index values are to be expected as a consequence of these enhancements to TACE. A number of test evaluations with these enhancements in place have been completed over the last few months and outcomes of this testing have been presented to the AngusNZ Board.