Estimation of GEBVs using deregressed individual cow breeding values

  • E A Mäntysaari
  • M Koivula
  • I Strandén
  • J Pösö
  • G P Aamand


Individual cow breeding values were deregressed using animal model and full national pedigree with 4.579 million animals. The deregressed proofs (DRPs) were used to recalculate the EBVs for their sires. The correlation between recalculated EBVs and original EBVs were 0.9997-1.0000, with small differences in EBVs of bulls without own daughters. Finally, the animal model DRPs were used to solve single-step genomic evaluations utilizing genotypes of 4725 bulls. The single-step approach was implemented using PCG algorithm and iteration on data. The Interbull GEBV test validation reliabilities for milk, protein and fat GEBVs were 0.35, 0.36 and 0.45, respectively. These were on average 0.03 higher than the single-step GEBVs with sire model DRPs. Overall the animal model deregression was computationally inexpensive. Also the single-step approach with 3.40 million cow records and three traits simultaneously took less than 1 hour wall clock time.