EN
The effect of the transition of dairy cows from pregnancy to lactation on the expression of genes encoding enzymes involved in hepatic glucose metabolism was studied. Six Holstein-Friesian heifers were used for this study. Liver samples were collected by biopsy on day 7 before expected parturition (-7) and days 3 and 21 after parturition (+3 and +21, respectively). The mRNA levels of pyruvate carboxylase(PC),phosphoenolpyruvate carboxykinase 1 (PCK1), phosphoenolpyruvate carboxykinase 2 (PCK2), lactate dehydrogenase B (LDHB),fructose-1,6-bisphosphatase 1 (FBP1) and glucose-6-phosphatase (G6PC) were measured using quantitative real-time PCR. The expression of PC and PCK2 mRNA on day 3 of lactation was significantly higher than that on day 7 before parturition (P<0.05) and slightly higher than on day 21 postpartum. The LDHB gene showed the highest expression level on day 3 of lactation, as compared with day 7 prepartum (P<0.001) and day 21 postpartum (P<0.001). No differences were shown in PCK1, FBP1 and G6PC expression levels between pregnancy and early lactation.