Interbull validation test for genomic evaluations

Abstract

Genomic evaluations (GEBV) can be validated by comparing GEBVs of bulls in the youngest age classes to the daughter yield deviations (DYD) that the bulls will receive later. The GEBV are calculated from truncated data where the last four years of phenotypic data are removed. The test consists of weighted linear regression of DYD on GEBV. The intercept, regression coefficient and the coefficient of determination R are interpreted to represent average bias, prediction bias, and the validation accuracy, respectively.