Changes in the blood routine, biochemical indexes and the pro-inflammatory cytokine expressions of peripheral leukocytes in postpartum dairy cows with metritis

Background The aim of the present study was to clarify the changes in complete blood count, blood biochemistry, and the gene expressions of pro-inflammatory cytokines of peripheral white blood cells in postpartum dairy cows with metritis. Results The cows were assigned to the control group (n = 28) or the metritis group (n = 28), retrospectively. Blood samples were taken 7 days before the estimated parturition (− 7 d), on the day of parturition (0 d), and 7 and 30 d after parturition. There was no difference in blood indexes between the control group and the metritis group at − 7 d. The WBC, granulocytes and monocytes were generally higher at 7 and 30 d in the metritis group than the control. In comparison with the controls, all liver function parameters and triglyceride levels at 0, 7 and 30 d, and the creatinine level at 7 and 30 d were higher in cows with metritis. The concentrations of Ca and P at 0, 7 and 30 d, and of glucose at 0 d were lower for cows in the metritis group compared with cows in the control group. Among these parameters, the WBC at 30 d, the aspartate aminotransferase activity (AST) at 7 d exceeded normal ranges (WBC: 5.0 ~ 16.0 × 109/L; AST: 42.5 ~ 98 U/L), whereas the concentrations of glucose and Ca from 0 to 30 d were below normal ranges (glucose: 2.5 ~ 4.5 mmol/L; Ca: 2.2 ~ 2.5 mmol/L) in the metritis group. The gene expressions of pro-inflammatory cytokines in the metritis group were higher than those in the control group, including the IL-1α at 7d, the IL-1β at − 7, 0 and 7 d, the IL-6 at − 7, 0, 7 and 30 d, the IL-8 at 0, 7 and 30 d, and the TNF-α at 7 and 30 d. Conclusion The cows with metritis experienced systemic inflammation for 4 weeks after calving, the impaired hepatic function, and the altered metabolic status with increased triglyceride level and decreased concentrations of glucose, Ca and P.