Incidence of clinical and subclinical hypocalcemia in dairy herds

摘要

Most cows experience transient hypocalcemia immediatelybefore and at onset of lactation due to production of colostrum. Incidence of clinical andsubclinical hypocalcemia in 952 cattle from 4 dairy herds were assessed within 48h of partus.Calcium levels varied from 6.86 ± 1.82 at 6 th lactation to 8.51 ± 1.24mg/dl at 1 st lactation. Bloodcalcium was negatively correlated with number of lactations (r =-0.342, p<0.01) and significantdifferent calcium values (P<0.001) were found at different lactations. Mean incidence of clinicalhypocalcemia was 4.94% and subclinical form, 34.24%. Number of lactations was related(P<0.001) with incidence of subclinical and clinical hypocalcaemia. Findings suggest that clinicaland subclinical hypocalcaemia increase with frequency of lactations.