|VAN DOORMAAL, B|
Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/5/2009
Publication Date: 7/12/2009
Citation: Schenkel, F.S., Sargolzaei, M., Kistemaker, G., Jansen, G.B., Sullivan, P., Van Doormaal, B.J., Van Raden, P.M., Wiggans, G.R. 2009. Genomic Evaluation of Holstein Cattle in Canada Utilizing MACE Proofs. Journal of Dairy Science. 92(E-Suppl. 1):396(abstr. W38).
Technical Abstract: Researchers in Canada and the United States are collaborating to develop and integrate genomic evaluations into their national genetic evaluations for dairy cattle in 2009. There are substantially more genotyped Holstein bulls with MACE proofs than with domestic Canadian proofs in Canada. The use of MACE proofs in addition to domestic proofs for estimating marker effects might, therefore, increase the reliability of genomic prediction in Canada. A validation study was carried out to assess the usefulness of MACE proofs for genomic prediction of 34 traits, including production, SCS and type traits. De-regressed proofs (DD)of genotyped bulls born between 1952 and 2000 (predictor bulls)with February 2005 domestic proofs (n=1,097)or alternatively with February 2005 domestic proofs or November 2004 MACE proofs (n=4,127) were used to estimated the effect of 38,416 SNP that were selected from the Illumina BovineSNP50TM chip used for genotyping. Then 2005genomic enhanced parent average (GPA)of younger proven bulls born between 2000 and 2004 (n=524) with domestic proofs in November 2008, but only a parent average available in 2005, were predicted using the estimated SNP effects. The squared correlation (r2) between GPA and the 2008 domestic DD was calculated. The average reliability of the DD of predictor bulls was 0.93, 0.88 and 0.89 for production, SCS, and type traits using domestic proofs only, and 0.82, 0.68 and 0.67 when MACE proofs were included. Despite the lower average accuracy of DD, the use of MACE proofs on average increased the r2 by 0.12, 0.10 and 0.06 points compared to the use domestic proofs only for production, SCS and type traits, respectively. Thus, the use of MACE proofs increased the prediction ability of GPA and, therefore, should be considered in the genomic evaluation of Holstein cattle in Canada.