A common reference population from four European Holstein populations increases reliability of genomic predictions

Table 2 Validation of parent index (PI) and genomic breeding values (GBV) using German (DEU_ref) and EuroGenomic (EU_ref) reference populations

Trait	Number of bulls				German reference				EuroGenomic reference
	DEU ref.	DEU val.	EU ref.	EU val.	REL_PI	b₀ /σ_g	b₁	REL_GBV-PI	REL_PI	b₀ /σ_g	b₁	REL_GBV-PI
Protein yield	3676	463	14475	1075	0.32	.29	0.83	0.28	0.32	.15	0.89	0.30
Udder depth	3672	454	14371	1048	0.22	-.08	0.97	0.26	0.20	-.16	1.01	0.45
SCS	3676	445	14479	1028	0.33	.04	0.83	0.26	0.33	.02	0.94	0.41
NRR	3676	314	14318	892	0.18	-.08	0.91	0.04	0.22	.11	0.91	0.14
Average	3675	419	14411	1011	0.26	.08	0.89	0.21	0.27	.03	0.94	0.32

REL_PI: r²_{(PI, DRP)}/REL_DRP, DRP is deregressed proofs in the validation dataset, REL_DRP is the average reliability of DRP; REL_GBV-PI : the difference between REL_GBV and REL_PI, where REL_GBV is r²_{(GBV, DRP)}/REL_(DRP); b₀ is intercept and b₁ is regression coefficient of DRP on GBV; σ_g is the genetic standard deviation

ISSN: 1297-9686