A number of major enhancements have been implemented in the December 2023 TransTasman Angus Cattle Evaluation (TACE) for Angus Australia and the New Zealand Angus Association. These are outlined below:
- Increased weighting on SNP genotype information in Single-Step BREEDPLAN: The relative emphasis given to pedigree and genomic information in the Single-Step BREEDPLAN evaluation has been modified so that stronger emphasis is given to the genomic data. Based on our test evaluations, some changes in the EBVs reported for individual animals are expected – especially those with a genotype but without performance records – while maintaining a high correlation of animal rankings overall. Increased accuracy in the EBVs reporting for genotyped animals, especially those currently reporting at low to mid accuracy, is also expected. These outcomes will depend on trait.
- Revised Single-Step Calving Ease analysis: Updated software to improve the efficiency of the SSCE analysis has been implemented, the goal being to reduce the amount of time taken for the analysis to complete. In addition, we have increased the weighting given to genomic information in the calculation of Calving Ease EBVs and accuracy. Based on our test evaluations, the increased weighting given to the influence of genomics will be the main source of change in EBVs and accuracy, all else being equal. Changes in Selection Indexes are to be expected if Calving Ease EBVs have economic weighting in the Selection Index.
- Enhanced Docility analysis: An enhanced Docility analysis has been implemented following review and endorsement by the MLA BREEDPLAN and Sheep Genetics Technical Committee. This enhancement includes genomic data and involves changes in the way the temperament scores are modelled in the analysis. The goal of these enhancements is to improve the efficiency of the Single-Step Docility analysis, with overall improvements to be expected in the accuracy of predictions based on Docility EBVs.
Changes in EBVs, accuracy and index values are to be expected because of these enhancements to TACE.
