Members are advised that some considerable modifications have been implemented into the software that is used to calculate the Calving Ease Direct and Calving Ease Daughters EBVs within the December 2019 Angus BREEDPLAN analysis.
Updated EBVs from this analysis will be published over coming days.
The modifications to the calving ease analysis software are part of the ongoing maintenance and improvement to the Angus BREEDPLAN genetic evaluation, and modernise the calving ease analysis software so that it is largely consistent with the software used to calculate the EBVs for other traits in the main component of the genetic evaluation.
The modifications to the calving ease analysis software include the implementation of:
- New EBV SOLVER
- Modelling of genetic groups
- Revised handling of calving difficulty scores
- Revised handling of genomic information
The modifications that have been implemented have resulted in considerable changes to the Calving Ease EBVs, and subsequently to the selection index values, for a large number of animals.
Of particular note is the considerable increase that has been observed in the standard deviation, or spread of Calving Ease EBVs. This is illustrated by an increase in the 1% percentile band for the Calving Ease Direct EBV increasing from +5.0 to +12.2. Similarly, the 99% percentile band for the Calving Ease Direct EBV has decreased from -7.6 to -13.9.
The increase that has been observed in the spread of EBVs has meant that while the Calving Ease EBVs for individual animals has changed considerably, their ranking by comparison to other Angus animals is very similar.
Importantly, the new Calving Ease EBVs provide a better estimate of each animal’s breeding value.
Further information regarding the modifications to the calving ease analysis software, along with a number of other analytical enhancements that have been implemented in the December 2019 Angus BREEDPLAN analysis, is available by clicking here.