Selenium (Se) is an essential trace element needed for normal growth and development (Sunde 1997, McDowell 2003, NASEM 2016). Over the past few decades, perceptions about Se have dramatically changed, ranging from Se being a nutrient that is potentially dangerous and should be controlled within narrow ranges to one that has many potential health benefits. Dietary biofortification is adding additional or elevated amounts of a dietary nutrient with the expectation of specific measurable positive outcomes. Regarding Se, dietary biofortification occurs either naturally with Se enriched ingredients or from direct dietary additions. Developmental programming is the concept that an insult or change during a critical window of fetal development can result in both short- and long-term consequences for the offspring. Recent data in developmental programming indicate that maternal nutrition plays a significant role in postnatal outcomes with lifelong consequences. Our laboratories have investigated Se biofortification of maternal diets during gestation with a focus on both maternal and offspring outcomes. Gestation is a critical time for livestock with the delivery of healthy offspring and a quick recovery of the mother being essential to successful livestock production enterprises. Our overarching hypothesis has been that additional Se in maternal diets would alter molecular, cellular, tissue, and whole animal events, and potentially mitigate compromised offspring outcomes resulting from compromised nutrient supply during gestation. This paper examines the impacts of maternal dietary Se supply (biofortification) during gestation on the offspring.