An oral calcium bolus (Bovikalc, Boehringer Ingelheim Vetmedica) supplying calcium to dairy cows in the form of calcium chloride and calcium sulfate was evaluated to determine the effect on calcium homeostasis immediately after calving. Cows in the treatment group received one bolus immediately after calving and a second bolus 12 hours later. Control cows received no calcium supplementation. Blood was analyzed for ionized calcium, and urine was collected for urinary pH determination. Postpartum supplementation with the Bovikalc bolus significantly increased serum ionized calcium levels and decreased urine pH values.