Genomics validation in modern Angus cattle

Genomics validation in modern Angus cattleBanner

Peer reviewed research conducted by the Animal Genetics & Breeding Unit has clearly demonstrated that the inclusion of genomic information increased the predictive ability of EBVs i.e. population based accuracies.  To learn more about the method used to determine this, READ THE PAPER. Please note, this is not referring to individual animal EBV accuracy increases.

  • Average increases in the predictive ability of accuracy of between 5 – 30% were observed, across breeds with the inclusion of genomics.
Figure 1: Average change in accuracy of validation animals across all traits by breed. Source: Johnston, D. J., Ferdosi, M. H., Connors, N. K., Cook, J., Girard, C. J., & Swan, A. A. (2023). BREEDPLAN single-step genomic evaluations deliver increased accuracies across all breeds and EBVs.

The increase in predictive ability that is observed from the inclusion of genomic information is largely determined by the size of the genomic reference population that is available for each breed:trait combination. A larger genomic reference population will generally have a larger increase in predictive ability but also relies on

  • Trait heritability  
  • Amount of genetic diversity present
  • Number of effective phenotypes collected 

The inclusion of genomic information increased the predictive ability of breeding values in the Angus breed on average by 25%, the increase observed varied from 7  to 37%, subject to the trait being analysed.

Figure 2: Increase in EBV accuracy, predictive ability, observed across traits with the inclusion of genomics.

Importantly the stability of EBVs increases with the incorporation of genomics. This means that with the inclusion of genomics the EBV was closer to the true breeding value and had less change after further data was added on itself and its relatives. 

While the inclusion of genomics increases the predictive ability of EBVs, EBVs do change with the inclusion of phenotypes and so a well-structured and planned phenotype performance recording strategy should be established for each herd to maximise their recording of effective data. 

The above does refers to population based accuracy not individual animal’s EBV accuracy. Further information about EBV accuracy values is available from the Angus Australia website. CLICK HERE to view these resources.