De-regressing MACE versus domestic EBV for genomics

Authors

  • Peter G Sullivan Canadian Dairy Network
  • Janusz Jamrozik Canadian Dairy Network
  • Gerrit J Kistemaker Canadian Dairy Network

Keywords:

de-regression, genomic evaluation

Abstract

De-regressed EBV are commonly used phenotypes in national genomic evaluation systems.  This study compared REML estimates of variance for de-regressed MACE proofs of foreign sires on the Canadian scale, versus de-regressed national EBV of domestic sires.  Variances for nearly all traits were higher for foreign than domestic sires.  Ratios of SD for foreign relative to domestic sires, based on December 2010 Holstein data were; 1.05 and 1.07 for protein and fat yields, 1.17, 1.04 and 1.24 for mammary system, feet & legs and conformation, 1.50 for cow survival and 1.20 for cow non-return rate.  Based on current data from December 2014, some of the more extreme ratios of SD were closer but still higher than 1.  After applying a variance adjustment to de-regressed MACE proofs of foreign sires, genomic validation results improved for all traits.  Slopes of regression, of the 2014 Canadian LPI index of trait EBV, on the 2010 genomic-enhanced parent averages (GPA), increased from 0.93 to 0.97, and biases of over-prediction for top young genomic bulls were accordingly reduced.

Downloads

Published

2015-08-12

Issue

No. 49 (2015): Proceedings of the 2015 Interbull Meeting

Section

Articles

License

Authors who publish with this journal agree to the following terms:

    1. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.

 

    1. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.

 

    1. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).