Abstract
Background: Two key findings from genomic selection experiments are 1) the reference
population used must be very large to subsequently predict accurate genomic estimated breeding
values (GEBV), and 2) prediction equations derived in one breed do not predict accurate GEBV
when applied to other breeds. Both findings are a problem for breeds where the number of
individuals in the reference population is limited. A multi-breed reference population is a potential
solution, and here we investigate the accuracies of GEBV in Holstein dairy cattle and Jersey dairy
cattle when the reference population is single breed or multi-breed. The accuracies were obtained
both as a function of elements of the inverse coefficient matrix and from the realised accuracies of
GEBV.