Adding genotypic and phenotypic information from cows to the reference population has the potential to increase the accuracy and decrease selection bias of genomic estimated breeding values (GEBV) in dairy cattle populations (Mc-Hugh et al. 2011; Thomasen et al. 2014; Wiggans et al. 2010). However, the cost of genotyping limits its use to an informative subset of animals (Boligon et al. 2012) and hence looking for an optimal strategy is crucial herein. Now a day, selective genotyping strategies (Boligon et al. 2012; Jiménez-Montero et al. 2012) and imputation methods (Calus et al. 2014) are some suggestive tools to reduce genotyping costs. Therefore, the aim of this study was to assess the effect of inclusion of cow genomic data in the reference population for genomic prediction under scenarios encompassing different selection strategies, number of genotyped cows and heritability on accuracy and bias of genomic breeding values when compared to the use of only bulls in the reference population.