In bovines, the transition period goes from the last three prepartum weeks to the first three postpartum weeks. This period is characterized by the metabolic adaptation of lipids, carbohydrates, minerals and proteins that try to balance the low intake of dry matter and the beginning of the secretion of milk. These changes are regulated by corticosteroids that are released at the time of birth. Some metabolites show noticeable changes in their blood concentration during this stage, which can lead to sanitary, reproductive and productive problems. The objective of the present work was to analyse the homeostasis in the transitional period, by determining the concentration of protein indicators, and some macrominerals, in dairy cows from two breeds under low- tropic conditions. The work was carried out in two commercial farms with similar management conditions in the Colombian south eastern region, in a agro-ecological zone of tropical dry forest according to Holdridge (1987), situated at 1,050 masl, with an average temperature of 23 oC and an annual rainfall of 1200 mm bimodally distributed. The feed consisted of Bermuda grass (Cynodon nlemfuensis). The present work used seven Holstein cows and seven Harton del Valle cows, from which blood samples were taken by coccygeal venepuncture in vacuum tubes, with heparin as anticoagulant and without anticoagulant, during the transition period, and up to the 60th day after delivery. A total of 156 samples were analysed. The following values were determined: total protein, albumin, globulin and urea; macro-minerals such as Ca, P and Mg and the cortisol hormone. The average values found for the Holstein breed were: total protein 66.7 g L -1