title: Application of single-step genomic best linear unbiased prediction with a multiple-lactation random regression test-day model for Japanese Holsteins.
abstract: This study aimed to evaluate a validation reliability of single-step genomic best linear unbiased prediction (ssGBLUP) with a multiple-lactation random regression test-day model and investigate an effect of adding genotyped cows on the reliability. Two data sets for test-day records from the first three lactations were used: full data from February 1975 to December 2015 (60 850 534 records from 2 853 810 cows) and reduced data cut off in 2011 (53 091 066 records from 2 502 307 cows). We used marker genotypes of 4480 bulls and 608 cows. Genomic enhanced breeding values (GEBV) of 305-day milk yield in all the lactations were estimated for at least 535 young bulls using two marker data sets: bull genotypes only and both bulls and cows genotypes. The realized reliability (R2) from linear regression analysis was used as an indicator of validation reliability. Using only genotyped bulls, R2was ranged from 0.41 to 0.46 and it was always higher than parent averages. The very similar R2were observed when genotyped cows were added. An application of ssGBLUP to a multiple-lactation random regression model is feasible and adding a limited number of genotyped cows has no significant effect on reliability of GEBV for genotyped bulls.
authors.affiliation: Holstein Cattle Association of Japan, Hokkaido Branch, Sapporo, Japan.
authors.forename: Toshimi
authors.initials: T
authors.lastname: Baba
authors.affiliation: Holstein Cattle Association of Japan, Hokkaido Branch, Sapporo, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Gotoh
authors.affiliation: Hokkaido Dairy Milk Recording and Testing Association, Sapporo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Hokkaido Dairy Milk Recording and Testing Association, Sapporo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: Hokkaido Dairy Milk Recording and Testing Association, Sapporo, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Abe
authors.affiliation: Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Masuda
authors.affiliation: Holstein Cattle Association of Japan, Hokkaido Branch, Sapporo, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Kawahara
mesh_terms: D000818:Animals; D001947:Breeding; D002417:Cattle / Q000235:genetics*; D066264:Datasets as Topic; D005260:Female; D055106:Genome-Wide Association Study / Q000379:methods*; D005838:Genotype; D007774:Lactation / Q000235:genetics*; D016014:Linear Models; D008297:Male; D008957:Models, Genetic; D015203:Reproducibility of Results
keywords: Holstein; random regression model; single-step genomic evaluation