Why EBI values of genomic sires have slumped by an average of €39
Evaluation of almost 1m more fertility records from the 2017 calving season added to an 15pc increase in the size of the sire reference population, has contributed to the downward adjustment in the EBI values of genomic sires by an average of €39 in new active dairy bull list for the coming breeding season.
Having delayed the release of the listing to include the latest statistics from calvings in 2017, ICBF brought forward the quarterly review due be published in May, which has been included in the release.
Topping the listing is the Co Kilkenny bred, Ballinteskin Arnold, bred by William Duggan, Hugginstown, a 59pc holstein, with EBI €259, combining €49 for milk, €207 for fertility and €33 for calving in the sub indexes.
Second is Nextgen YKG Candy 493, another 59pc Holstein, bred in the Teagasc Moorepark Herd with an EBI €282, including €67 for milk, €164 for fertility and €33 for calving in the sub indexes.
The breding body points out that the listing contains a number of notable improvements compared to previous years, in time for the current breeding season, which had not been anticipated for release until the next evaluation due in May 2017.
These include the inclusion of 2-year old bulls on the listing for the first time (due to these bulls now having their first official evaluation for calving difficulty based on calves born just this Spring), more accurate genomic proofs for AI sires due to a number of improvements having being made by ICBF and Teagasc to the genomic evaluation system over the past 4 months and a 15% increase in the size of the sire reference population against which the genomic prediction equations are generated as well as the inclusion of almost 1m more fertility records from the 2017 calving season to date and updates to the genomic evaluation systems and software from which the evaluations are generated.
The average drop of €39 in EBI is equivalent to about two days in calving interval and 1% for survival and has been based on the weighted average reduction in EBI value for the 285 GS sires that are currently available in ‘Active AI’.
ICBF points out that some bulls will drop more and others less than this average figure, depending primarily on how the sires of these young GS bulls are performing on farms.