Milk production systems in Brazil are based, for the most part, on the use of tropical grass pastures as the main source of nutrients for animals. Keeping high levels of pasture-based milk production depends on the following factors: supply of forage in quantity and quality, maximum duration of the grazing season, rational use of energy, protein and mineral supplements, and definition of management strategy that aims at productivity by area. Therefore, intensive pasture management results in forage of better nutritional value, which implies in changes in concentrate supplementation, in which energy is the main limiting factor. Thus, the productive and economic efficiencies of a milk production system are related to the establishment and management of productive pastures, in order to allow the animals to be able to select good quality forage and sufficiently offered to supply an expressive fraction of the diet. The cultivar BRS Kurumi, developed by Embrapa's Elephantgrass Genetic Improvement Program, presents reduced height (dwarf), being adapted for grazing. It is noteworthy that, although there is information on the performance of dairy heifers managed on BRS Kurumi elephantgrass pasture, with positive results, information is lacking on productive performance and lactating cows. This cultivar is characterized by high biomass production and excellent pasture structure, with a high proportion of leaves and reduced elongation of the stem and high nutritive value, with contents of 20.5% crude protein, 53.6% neutral detergent fiber and 59.7% total digestible nutrients. Based on such chemical composition, the cultivar has the potential to allow production levels of 16-17 L milk/ cow / day, using only mineral supplementation. Thus, this project aims to evaluate the foraging potential of elephantgrass cultivar BRS Kurumi for milk production, generating important information about its management under rotational stocking grazing with lactating cows and the effect of concentrate supplementation during the rainy season, in order to allow the adjustment of diets, making them economically and nutritionally efficient, and increasing the competitiveness of pasture-based milk production systems. Hence, this study focuses on the following trends: the foraging potential of elephantgrass BRS Kurumi pasture for milk production and the effect of energetic supplementation on the performance of lactating cows grazing elephantgrass BRS Kurumi, based on nutrient intake, milk production and composition, changes in body weight, energy expenditure, and blood metabolic parameters; to study the bioeconomic viability of energetic supplementation for lactating dairy cows in BRS Kurumi elephantgrass pasture during the rainy season; and disseminate the technologies generated in this project aiming at the maximum economic and productive efficiency of pasture-based milk production system. The following results are expected: to define the foraging potential of BRS Kurumi pasture for milk production; to define the BRS Kurumi pasture supplementation strategy aiming at the competitiveness of milk production systems; to evaluate the bioeconomic viability of the use of concentrate supplementation and to define the use of the latter according to the economic scenarios, based on input-output (milk) price relations; and disseminate the technologies generated in this project to farmers and technicians (multiplier agents). The information generated will contribute to complement the technology package to guide the efficient use of BRS Kurumi pasture in milk production systems.