Peripartal alterations of calcitonin gene-related peptide and minerals in dairy cows affected by milk fever.

BACKGROUND: Milk fever, a metabolic disease of dairy cattle, is associated with perturbations of calcium homeostasis, the pathogenesis of which is not yet completely understood. OBJECTIVE: The aim of this study was to investigate plasma concentrations of calcitonin gene-related peptide and selected minerals and metabolites in periparturient cows with and without milk fever. METHODS: Plasma concentrations of calcitonin gene-related peptide, as well as calcium, phosphate, magnesium, iron, glucose, lactate, and cortisol, were determined in multiple plasma samples from Jersey cows with and without spontaneous milk fever. RESULTS: Cows affected by milk fever (n = 5) had lower concentrations of calcitonin gene-related peptide (P = .038) and inorganic phosphate (P < .001) in plasma than did the controls (n = 5). Also, these cows tended to have lower calcium concentrations (P = .071). Magnesium, iron, lactate, glucose, and cortisol concentrations were comparable between both groups of cows (P > .10). Around the day of calving, plasma concentrations of lactate, glucose, and cortisol increased and the concentration of iron decreased in all cows (P ≤ .01). CONCLUSIONS: Despite the limited number of cows evaluated, this report is the first to indicate lowered concentrations of calcitonin gene-related peptide as part of the metabolic changes during milk fever in cows. Further work with a larger cohort of animals is warranted to understand the precise role of calcitonin gene-related peptide and the potential associations with disturbances in plasma minerals typically observed during milk fever.