Serum 25-hydroxyvitamin-D concentrations in beef cattle herds in which ruptures of the Achilles tendon had occurred.

The frequency of skeletal disorders including ruptures of the Achilles tendon has increased during the last years in Swedish beef cattle herds, especially in intensively raised calves. The serum concentrations of 25-hydroxyvitamin-D, calcium and inorganic phosphorus were analysed in 7 affected and 3 control herds. None of the animals in affected herds had detectable amounts of serum-25-OH-D (≤ 2 ng/ml) while the control animals had a concentration of 36.1 ng/ml (least squares mean). Calcium and inorganic phosphorus were also significantly lower in the affected herds (P ≤ 0.001). In 1 herd the animals were randomly divided into 4 groups and treated in one of the following ways: Orally with vitamin ADE or D, intramuscularly with D or D. The effect of treatment on serum Ca and P was measured 1 month later and was found to be equally high in the 4 groups.