Effects of injectable mineral supplementation on health, metabolic stress, and performance in Holstein cows during the transition period

Metabolic distress in dairy cows during the transition period is associated with a high incidence of infectious diseases and reduced performance. This experimental field trial evaluated the use of injectable mineral supplementation (IMS) to prevent metabolic distress in Holstein cows during the transitional period. The IMS group (n = 189) received three injections (10 mL) of a multi-mineral supplement (Fosfosal, Virbac Brazil, São Paulo, Brazil) at days − 14, 0 (calving day) and + 14 days after parturition. The non-supplemented group (NIMS; n = 123) received three placebo injections. Productive, health, and reproductive performances were assessed along with metabolic distress biomarkers in a subset of cows (NIMS, n = 32; and IMS, n = 34). IMS cows had lower incidences of persistent hypocalcemia and metritis, along with reduced haptoglobin, higher glucose, and lower beta-hydroxybutyric acid (BHB) concentrations. The IMS group had higher enzyme activities for glutathione peroxidase (GPx), reduced glutathione (GSH), and higher immunoglobulin G (IgG) concentrations. Mineral supplementation did not affect milk production, somatic cell count (SCC), or reproductive performance. In conclusion, IMS-supplemented cows showed improved immunity, characterized by an anti-inflammatory profile, higher IgG concentrations, reduced lipid metabolism, and oxidative stress, positively affecting their overall health.