In ruminants, adequate fetal and post-natal development of adipose tissues (AT) is a major challenge to promote metabolic adaptation both at birth for neonate survival (especially in sheep), and in adult life for productive efficiency during the pregnancy-lactation cycle of dairy females or for carcass yield and quality of meat animals. The factors that determine AT mass in adult mammals are not fully understood. Both epidemiological and fetal programming studies in ruminants suggest that fetal growth of ATs impacts their postnatal growth and therefore the body fat mass or adiposity (Bonnet et al., 2010). A prerequisite to understand the mechanisms of fetal programming of AT growth is to improve our knowledge on the mechanisms underlying the AT growth in fetus, which are still very poorly known whatever the species. In this context, our objective was to identify the cellular and molecular mechanisms that sustain the fetal AT growth in bovine and to study its variability.