The transition from pregnant non lactating condition to non pregnant lactating status is a period of dramatic changes for the cow, which has to adapt its metabolism to the strong requirements for milk production. From the equilibrium that the cow resolves this period will depend the capacity to maximize milk production and quality, to evade metabolic diseases and ensure the following pregnancy. The nutritional improvement, genetic selection and animal management have in-crease milk production in the last decades and this is associated with a decrease in the reproductive performance and in the increase of health diseases. This review summarizes the studies performed in the last years in Uruguay, with emphasis in nutritional management, ingestive behaviour, endocrine and molecular mechanisms of nutrient partitioning and its rela-tion with fertility in dairy cows. Studies that investigate the productive efficiency of different dairy biotypes and breeds are reported. Studies in the cow´s health that identify the transition period as a risk factor for metabolic, infections and traumatic diseases are included. We conclude that studies that integrate problems of national relevance are the appropriate meth-odology to investigate complex biological systems as is the dairy cow during the transition period under grazing conditions.