Genomics in TACE: For understanding relationships, not replacing phenotypes
Genomics are enhancing Estimated Breeding Values (EBVs) from the TransTasman Angus Cattle Evaluation (TACE) through more precise understanding of the relationships between animals. Importantly, phenotypes (i.e. performance data) remain as a critical component in TACE and are not replaced by the incorporation of genomics.
Christian Duff, General Manager Genetic Improvement said “TACE has utilised genomics under the single-step approach since December 2017, however there are still some misconceptions on how genomics are utilised in the genetic evaluation. With close to 350,000 genotypes now included in TACE, it’s important we understand how this data is used to enhance our EBVs”
“A misunderstanding that we are currently hearing is that genomics replace phenotypes, or performance data, in the evaluation. This is incorrect. Without phenotypes, both now and into the future, our EBVs would have significantly lower accuracy and eventually have no value at all. This would be the case whether evaluated with pedigree-based relationships or genomic relationships or a combination of both, like we do in a TACE single-step evaluation model.” Mr Duff added.
“Genomics boosts the TACE genetic evaluation through a more precise understanding of the relationship between animals, both within the pedigree and outside of the pedigree. This is important when you have well established and comprehensive genotype and phenotype reference population like do at Angus Australia with the Angus Sire Benchmarking Program (ASBP), coupled with aggregated data from Angus Australia members. Genomics allows Angus animals to link more effectively to that reference population, than would pedigree alone.” Mr Duff states.
Mr Duff adds “I expect some of the confusion has arisen when Angus Australia enhanced the TACE evaluation in December 2023 by increasing the genomic relationship weighting from 0.5 to 0.95. This simply means the evaluation places more weighting on genomics to understand relationships, compared to pedigree, when both are available. It has no direct impact on how phenotypes are used in the evaluation”.
“One major benefit we see with this TACE enhancement is that members and industry have access to significantly higher accuracy EBVs on younger animals, particularly those that are genotyped. Having access to higher accuracy information for selection of young breeding animals is the holy grail of livestock breeding. I encourage all members to be excited, not anxious, by this outcome and to use it to the advantage of their breeding program.”
Mr Duff concluded “Angus Australia’s extension team, along with industry collaborators, have developed a comprehensive suite of information to help producers understand how genomics are used in genetic evaluations, including TACE. I encourage members to utilise the resources and follow up with Angus Australia if they have further questions.
Angus Australia Contacts:
Nancy Crawshaw, Acting Extension Manager: 0436 337 652
nancy.crawshaw@angusaustralia.com.au
Hanlie Jansen, Extension Officer: 02 6773 4641
hanlie.jansen@angusaustralia.com.au
Christian Duff, General Manager – Genetic Improvement: 02 6773 4620
christian@angusaustralia.com.au
Access the Understanding Genomics in TACE: What, How, Why and When Education Module
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