Biochemical markers of bone metabolism in dairy cows with milk fever

Abstract

Bone metabolism was investigated in 8 healthy and 12 dairy cows suffering from milk fever (MF) in intensive dairy production. Blood samples were taken within 48 hours after calving in healthy cows and before treatment in cows with MF. Bone and mineral metabolism were evaluated by measuring blood serum bone resorption biomarker Cterminal telopeptide of type I collagen (CTx) and bone formation biomarker bone-specific alkaline phosphatase (bALP) beside the classical panel: total calcium (Ca), inorganic phosphate (iP), magnesium (Mg) and alkaline phosphatase (ALP). The results were statistically analyzed and compared between the two groups. Mean Ca value in cows with milk fever was 1.01±0.29 mmol/L and in healthy cows it was significantly (p<0.05) higher (1.94± 0.04 mmol/L). All the cows were also hypophosphatemic with lower phosphorus values (p<0.05) in MF cows. Some cows with MF were also hypermagnesemic, but the difference in Mg concentrations between the two groups was not significant. Mean total ALP and bALP activity were higher in cows with MF (65±17.7 U/L and 21.3±8.5 U/L, respectively) than in healthy cows (55.9±7.0 U/L and 20.5±8.9 U/L, respectively). The mean concentration of blood serum CTx was lower in cows with MF (0.212±0.091 ng/L) than in healthy cows (0.417± 0.252 ng/L), but as for bALP not significantly.