Postpartum macrominerals and trace elements dynamics in cows: A potential early indicator of endometritis?

This study aimed to investigate whether the changes in the concentrations of macromineral (Ca, P) and trace element (Fe, Zn, Cu) in cows during the postpartum (pp) period could serve as early indicators of endometritis. A total of forty Brown Swiss cows were evaluated for endometritis using rectal, vaginal and ultrasonographic examinations on pp day 28 and were divided into the following groups: Mild (n = 10), moderate (n = 10), severe (n = 10) endometritis and, control (n = 10) groups. The serum concentrations of Ca, P, Fe, Zn, and Cu were assessed at various pp time points (days 0-7, 14, 21, and 28), and notable alterations were detected in the endometritis groups. Compared to the control, Ca were significantly lower in the endometritis groups, particularly between days 1-5 and on day 21. Likewise, the concentrations of Fe, Zn, and Cu were lower in the endometritis groups, particularly on days 14 and 21. Furthermore, Receiver Operating Characteristic (ROC) analysis demonstrated that Ca, P, Fe, Zn, and Cu had significant diagnostic value for endometritis at specific pp time points. Specifically, Ca achieved the highest diagnostic accuracy on day 14 (AUC=0.920), P on day 21 (AUC=0.910), Fe on day 14 (AUC=0.950), Zn on day 28 (AUC=1.000) and Cu on day 21 (AUC=1.000). In conclusion, the serum Ca, P, Fe, Zn, and Cu concentrations during the pp period can be used as potential early diagnostic biomarkers for endometritis in cows.