ABSTRACT. Single step genomic methodology provides a unified framework to integrate phenotypic, pedigree and genomic information in prediction of breeding values for all individuals and in estimation of marker effects. Computational tools for the implementation of the single-step methodology are presented. Methodology, quality control of samples and different options to create genomic relationship matrices are discussed. Computing time for construction and inversion of genomic relationship matrices and large-scale genome-wide association study for heat tolerance in milk yield are presented.