Epigenetics is not a commonly used in the selection of parents to breed the next generations. That is surprising as epigenetics can influence gene function, is inherited via mitosis and/or meiosis and can occur both from the female and male lines. Epigenetics have been shown to affect gene-expression and can thereby play a strong role on the construction and plasticity of phenotypes in many plant and animal species, including poultry. In this chapter, we underline the key components in the poultry production chain where epigenetics can play a role. We highlight conditions influencing early-life programming by parental nutrition, thermal conditioning, and stressful events in the (grand)parents which are known to influence behaviour and welfare. We conclude that in the analysis of phenotypic variation one should consider both epigenetics and genetics, as epigenetics could explain a part - still to be estimated - of the variability of complex phenotypic traits.