Validation of genomic predictions in German Holsteins for all traits

  • S Rensing
  • Z Liu
Keywords: Holsteins, genomic predictions, validation

Abstract

Genomic enhanced breeding values (gEBV) for Holsteins are official in Germany since August 2010. Independent gEBV in April 2010 of 1,374 German A.I. bulls derived from the validation for the ICAR/Interbull test for the German Holstein genomic evaluation system were compared with their official daughter based gEBV from August 2011. Traits were the milk production index RZM, total conformation index RZE, relative breeding value somatic cell score RZS, combined longevity RZN and daughter fertility index RZR. For all traits differences between means for gEBV without and with daughter information were very small indicating no bias. The same was observed for the top-100 bulls for RZM whereas the top bulls for the other traits seemed to be slightly overestimated by 0.1 (RZE) to 0.2 (RZN) genetic standard deviations (sg). Standard deviation of difference (SD) ranged from below 0.5 for RZS and RZR to 0.68 sg for RZM. There were indications that gEBV without daughters predict later highly reliable daughter based gEBV better than the first daughter based proofs.