Abstract
Prepartum negative energy balance (NEB) in dairy cows is caused by the increased demand of energy due to the rapid growth of fetus and decreased feed intake. However, the etiology of prepartum NEB and its association with postpartum NEB are not well understood. This study was conducted to determine the association between pre- and postpartum NEB in dairy cows. Cows were allocated into four groups based on the blood glucose (GLU) and nonesterified fatty acid (NEFA) profiles at 2-0 wk prior to calving: Group I (n=23; low GLU, high NEFA); Group II (n=30; low GLU, low NEFA); Group III (n=15; high GLU, high NEFA) and Group IV (n=24; high GLU, low NEFA). GLU showed lower levels in Groups I and II compared to Groups III and IV at 2 to 4 wk after parturition, whereas NEFA was higher in Groups I and II compared to Group IV at 0-2 and 2-4 wk after parturition. Aspartate aminotransferase (AST) in Group II was higher than that in Groups III and IV at 2-4 wk postpartum, and g-glutamyl transferase (GGT) was higher in Group I compared to Group II at 2-4 wk postpartum. In total, we found a negative correlation between GLU and AST and a positive correlation among NEFA, AST and GGT after parturition. These results suggest that NEB at 2-4 wk postpartum is closely associated with NEB at 2-0 wk prepartum, and high postpartum NEB is associated with decreased liver function.
