The evaluation of superoxide dismutase activity, neutrophil function, and metabolic profile in cows with retained placenta.

The present study aimed to determine the alterations in pre- and postpartum immune function, superoxide dismutase (SOD) activity, and serum metabolite changes in Brown Swiss cows with or without retained placenta (RP). Peripheral blood was sampled at -10 ± 4 days antepartum and 10 ± 4 days postpartum for the assessment of neutrophil phagocytic and oxidative burst activities by using flow cytometry. SOD activity, beta hydroxybutiric acid (BHB), nonesterified fatty acids (NEFA), calcium (Ca), phosphorus, aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), creatinine kinase (CK), gamma-glutamyl transferase (GGT), lactate dehydrogenase, bilirubin, cholesterol, glucose, urea, albumin, total protein, and triglyceride concentrations were also measured from serum samples collected at -10 ± 4, 3 ± 1, 10 ± 4, and 30 ± 4 days relative to parturition. All data were analyzed using the MIXED procedure of SPSS. Neutrophil phagocytic and oxidative burst activities, phagocytic and oxidative fluorescence intensity, and phagocytic and oxidative indexes were similar among the groups (P > 0.05). However, serum SOD activity was 30 ± 4 IU/ml and 17 ± 2 IU/mL for cows that subsequently developed RP and healthy cows at -10 ± 4 days antepartum, respectively (P < 0.05). Body condition scores were similar in both groups (P > 0.05). All investigated serum metabolic parameters varied significantly over time (P < 0.001). Cows affected with RP had subclinical hypocalcemia (8.06 ± 0.3 mg/dl) and had significantly higher BHB levels (1027 ± 137.9 mmoL/l) at 3 ± 1 days postpartum. Furthermore, these cows had greater AST and NEFA concentrations around calving (P < 0.05). In conclusion, retained placenta had no prolonged effect on the measures of neutrophil function during the postpartum period. On the other hand, increased antepartum SOD activity might be a predisposing factor and can be used as a predictive biomarker for retained placenta.