Metabolomic fingerprinting of milk fever cows: Pre- and postpartum metabolite alterations

Background: Milk fever (MF), a metabolic disorder in dairy cows characterized by low blood calcium concentrations postpartum, is well-recognized clinically. However, comprehensive data on the alteration of metabolites associated with this condition remains sparse. Hypothesis: Delineate serum metabolite profiles and metabolic pathways preceding, coinciding with, and after the onset of MF. Animals: Twenty-six cows, including 20 healthy cows and 6 cows initially affected by MF. Because of culling, the number of MF-affected cows decreased to 4 at MF week, +4 weeks, and +8 weeks postpartum. Methods: A nested case-control longitudinal study was conducted, with blood samples collected at −8 and −4 weeks prepartum, MF week, and +4 and +8 weeks postpartum. Serum analysis utilized direct injection/liquid chromatography/tandem mass spectrometry (DI/LC/MS/MS) techniques. Results: Key findings included the identification of diverse metabolites such as hexose, amino acids, phosphatidylcholines, lysophosphatidylcholines, and sphingomyelin, which varied between studied groups (P <.05). The most marked metabolic alterations were observed 4 weeks prepartum. In total, 42, 56, 38, 29, and 24 metabolites distinguished the MF group at the respective time points (P <.05). Additionally, 33 metabolic pathways, including amino acid, antioxidant metabolism, fatty acid degradation, and carbohydrate processing, were impacted (P <.05). Conclusions and Clinical Importance: Metabolic disruptions in dairy cows begin several weeks before the clinical manifestation of MF and persist up to 8 weeks postpartum. These findings emphasize the complexity of MF, extending beyond only hypocalcemia and indicate the necessity for preemptive monitoring in dairy herd management.