Abstract
Changes in maternal nutrition that represent inadequacies or excesses in nutrient supply have been implicated in altered fetal development as well as offspring outcomes and have been termed fetal or developmental programming. Research in the area of developmental programming of livestock has greatly increased during the last two decades. For ruminants, most research efforts in developmental programming have focused on nutritional perturbations during the last two-thirds of gestation. Unfortunately, research investigating changes to maternal nutrient supply during early gestation or even periconceptually has been limited. The objectives of this invited review are to provide a summary of our current understanding of the impacts of inappropriate maternal nutrition during early gestation on embryo-fetal and offspring developmental outcomes. Nutrient supply to the conceptus varies during the time of early placental and conceptus development, and uterine glandular secretions, often called uterine milk or uterine histotroph, are major suppliers of nutrients during this time. Nutrients in histotroph are essential to conceptus development, and histotroph nutrient concentrations may be responsive to maternal nutrient supply. As the placenta develops and becomes fully functional, fetal nutrient supply becomes dependent on placental function. Research investigating changes in total maternal nutrient supply, even during early gestation, has clearly demonstrated impacts on offspring outcomes. Investigations into supply of specific nutrients and development outcomes have increased rapidly in recent years with results demonstrating that in some cases, even small changes in supply can have consequences on offspring development. Underlying mechanisms of developmental programming are associated with epigenetic events partially driven by methyl donors and cofactors. Emerging knowledge associated with the influence of periconceptual, fetal, and neonatal nutrition on offspring development, postnatal health, function, and productivity is creating opportunities for enhanced livestock production through strategic nutrient supplementation.