Does increased immune response at early postpartum period have a relationship with metabolic markers and subsequent fertility?

The aim of the present study was to investigate blood parameters and subsequent fertility in cows with or without increased postpartum polymorphonuclear neutrophil activity. The study was conducted with 15 Brown Swiss cows between 1-3 lactations. Polymorphonuclear neutrophil activities were assessed at 10±4 days before and after parturition. The cows which maintained their phagocytic and oxidative burst activites compared to the prepartum period were classified as control (CON), and cows which increased phagocytic and oxidative burst activites were defined as increased cellular immune response (ICIR) cows. Energy, protein metabolism markers, hepatic enzymes, blood mineral levels and body condition scores were measured at -10±4, 3±2, 10±4 days relative to parturition. Pregnancy rates, the number of inseminations, and calving to pregnancy intervals were evaluated. The mean non-esterified fatty acid (NEFA) and beta- -hydroxybutyric acid (BHB) concentrations were lower in ICIR cows. Mean serum calcium (Ca) concentrations were in subclinical hypocalcemia level at day 3±2, 10±4 days postpartum in CON cows. Postpartum immune cell functions and NEFA, BHB concentrations were negatively cor- related. The calving to pregnancy interval were longer in the control cows. However, total preg- nancy rates and the number of insemination in both groups were similar. In conclusion, postpar- tum polymorphonuclear neutrophil activity is affected by periparturient metabolic status. Postpartum energy metabolites negatively affected the postpartum cellular immune response. The increased postpartum polymorphonuclear neutrophil activity at early postpartum period is positively related with subsequent fertility in dairy cows.