Effect of postparturient oral calcium administration on serum total calcium concentration in Holstein cows fed diets of different dietary cation-anion difference in late gestation.

Abstract

Minimizing the severity of post parturient hypocalcemia and the incidence of subclinical hypocalcaemia in multiparous dairy cows are important goals of the transition period. The primary objective of this study was to determine whether feeding an acidogenic ration in late gestation combined with oral CaCladministration after parturition improved calcium homeostasis when compared to feeding an acidogenic ration prepartum or oral CaCladministration postpartum alone. Forty-two Holstein dairy cows were randomly assigned to one of three groups of 14 cows. Group L were fed a low DCAD ration. Groups L+Ca and M+Ca were fed a low or moderate DCAD ration, respectively, and administered 50g Ca as a CaClsolution at calving and 12h later by ororuminal intubation in 500mL of water. Mean serum [calcium] was lower immediately after parturition in group M+Ca (7.1mg/dL) than group L+Ca (8.2mg/dL). Oral CaCladministration increased mean serum [calcium] at 6h after treatment in groups M+Ca (8.0mg/dL) and L+Ca (8.7mg/dL), but most of this increase had disappeared at 12h after treatment. Group L+Ca had a higher serum [calcium] at time=6h and 12h than the other two groups, and a higher serum [calcium] than group M+Ca at 1 and 2days after treatment. We conclude that feeding an acidogenic ration in late gestation combined with oral CaCladministration provided a higher serum [calcium] at 6 and 12h after parturition than feeding an acidogenic ration prepartum or oral CaCladministration postpartum alone.