Energy is a fundamental nutrient for the development and fattening of cattle in housing and grazing conditions; however, this component in rations where corn or sorghum is used, has had an impact on the increase of production costs. Gluconeogenic substrates are a new energetic, sustainable and economic alternative to be used in cattle fattening. These substrates can replace up to 60% of the energy required by cattle in their rations, without detriment to weight gains, feed conversion rate and cost-benefit for the beef producer. In the present text, a series of research works are included where gluconeogenic substrates are used in diets for fattening cattle in grazing and stall systems.