Free fatty acid-induced hypocalcemia in food-deprived dairy cattle.

Food deprivation in 6 dairy cows caused significant increases (P greater than F = 0.0054) in serum free fatty acid concentrations, but did not cause clinically important decreases in serum ionized calcium concentration. Several determinants, including blood pH, serum albumin, and serum bicarbonate were studied as factors that could potentially alter calcium ion concentration. Although several changes were significant, they were small and were not considered to be clinically important in the context of calcium-ion binding. It was concluded that free fatty acid binding of calcium ion did occur, but that such binding did not contribute significantly to the etiopathogenesis of calcium responsive midlactational downer cow syndrome.