25-OH-D3 concentrations in serum from healthy and paretic post parturient cows.

The serum 25-OH-D3, Ca, P, and Mg concentrations in thirty-seven cows that had calved in March--April were studied in this trial. Twenty-three had puerperal paresis. Values observed in this group were Ca, 1.27 +/- 0.3 mmol/l, P, 1.63 +/- 0.82 mmol/l, Mg, 1.14 +/- 0.27 mmol/l, and 25-OH-D3, 32.7 +/- 22 micrograms/l. In the fourteen age-matched healthy control cows from the same herd values were Ca, 1.93 +/- 0.5 mmol/l, P, 3.09 +/- 1.28 mmol/l, Mg, 1.01 +/- 0.3 mmol/l and 25-OH-D3, 31.5 +/- 19.7 micrograms/l. The range of values for the cows serum 25-OH-D3 concentration was less than 3.2 to 76 micrograms/l. No differences could be established in terms of 25-OH-D3 concentrations between the groups.