ABSTRACT.- This study identified the relationship between energy balance and some blood metabolites in primiparous dairy cows with different calving conception interval. Twenty primiparous Holstein-Friesian dairy cows were grouped according to the interval (days) from calving to conception into early-conception (early-c; 150 days) group; and evaluated on day-7 prior to parturition, and days 28, 56 and 90 postpartum. All groups presented positive energy balance, serum concentrations of HDL, urea-N and progesterone with no difference on days 28 and 56 of lactation. On day 90 of lactation all the cows presented negative energy balance; however, the early-c group presented a less intense (P 150 dias); e foram avaliados no dia -7 pré-parto, e nos dias 28, 56 e 90 dias pós-parto. Todos os grupos apresentaram balanço energético positivo, concentrações séricas de HDL, N-uréia e progesterona sem diferença nos dias 28 e 56 de lactação. Aos 90 dias de lactação todas vacas apresentaram o balanço energético negativo, porém o grupo de vacas precoce foi menos intenso (P
Instituto Nacional de Investigación Agropecuaria