Abstract: | The association between blood calcium levels and electrocardiographic variables was
compared in 137 normal parturient and 36 peripartum recumbent Holstein cows to determine
whether hypocalcemia in peripartum dairy cows can be rapidly diagnosed using
electrocardiograph. Inverse of STc (ST peak interval/SS interval0.5) and blood
ionized calcium or serum calcium concentrations were strongly correlated, and both
correlation coefficients were 0.81 (P<0.001). The 95% prediction
interval indicated that cows with STc >0.385 ± 0.001 sec are very likely to be
hypocalcemic (blood ionized or serum calcium concentrations of <0.9
mmol/l or <7.5 mg/dl, respectively). These findings
indicate that hypocalcemia in parturient cows can be non-invasively estimated using the
STc. |