The purpose of this study is to investigate the potential modifications in the epigenome of the gametes and early embryos in dairy heifers and bull at an age where gametes collection becomes possible. An epigenetic analysis involves the examination of DNA methylation by a direct process: the measure of methylated DNA in the genome and by an indirect process: the measure of gene expression (transcriptome) in day 6 embryos as gametes do not express genes. Bull sperm will be collected at 10-12-16 months of age and each animal will be its own control to define the age effect. Semen will be firstly analysed for potential epigenetic differences according to age and then in IVF: young bulls will be used with oocytes from adult cows. In addition follicular gene expression will be analyzed in embryos at the blastocyst level. EmbryoGENE has developed 2 unique platforms, one in transcriptomic analysis and one in epigenetic analysis for scientists to perform such experiments. According to the international scientific committee of EmbryoGENE, we are actually the best equipped in the world to do these types of studies and this would bring Canada to the leading position in this field. The result will define the risk of using younger animals and, if present, treatment options or industry guidelines to manage or control these risks.