One hundred and eighteen Holstein cows were used to evaluate the effects of body condition score at parturition on milk production and fat content, blood beta-hydroxybutirate (BHBA), glucose and aspartate-aminotransferase (AST) and disease occurence in early lactation. According to their body condition score (BCS) at calving, 1 (thin) at 5 (fat), the cows were alloted in two groups: I) composed by BCS > or = 4,0; and II) composed by BCS <= 3,5. The BCS were 4.2 and 3.2 for the group I and II, respectively. The BCS at calving did not affect milk production, milk fat, plasma glucose and AST and disease occurence in early lactation. However, the group I had higher (P<0.0084) BHBA and lost more (P=0.01) weight. When the analysis was performed weekly the BHBA for the group I was higher until three weeks post-partum, showing a peak at first and second week for both groups. The group I also had lower levels of plasma glucose in the first and second weeks, showing a intense negative energy balance in this period.
body condition score; dairy cows