As outlined in a recent web post on 07th August, we are currently in the process of implementing an improvement in the way that we calculate genomic EBI’s for dairy animals. This improvement involves limiting the weighting placed on the genomic component of an animal’s EBI back to 70% for the milk traits and 50% for the fertility traits.
This improvement will correct for the current prediction bias which was always present, particularly in the fertility proof, and will result in an average drop of €22 and €37 in EBI for 2018 and 2019 born AI bulls, respectively.
As highlighted by Professor Donagh Berry in our recent Dairy Genomics Webinar, the challenge around prediction bias and its subsequent correction process has been experienced globally in countries such as Germany, The Netherlands and the US.
The main reason for the increase in the fertility prediction bias is as a direct result of the large increase in genomic AI usage over the last few years, as well as the inclusion of genomic females into the training population.
While these changes are being implemented, weekly genomic evaluations will cease from today and will recommence again after the next genetic evaluation run which will be published on the 6th October.