Oral administration of calcium salts for treatment of hypocalcemia in cattle.

Milk fever is usually treated by i.v. administration of 8 to 10 g of Ca. Oral Ca salts have been suggested as an alternate treatment for milk fever. In our studies, plasma Ca concentration changes effected by various oral Ca preparations were compared. Solutions were administered by oral drenching of cows, and blood was obtained hourly. Calcium chloride increased plasma Ca better than Ca propionate, which increased plasma Ca better than Ca carbonate. A CaCl2 gel formulation increased plasma Ca better than Ca carbonate, but not as well as did Ca propionate. Concentrated solutions of Ca as CaCl2 increased plasma Ca better than diluted solutions. Rumen bypass of Ca salts increased plasma Ca concentration more than when Ca salts were placed into the rumen. Oral administration of 50 g of Ca as CaCl2 raised plasma Ca concentrations to the same extent as 4 g of Ca as CaCl2 given i.v. We also examined effects of oral Ca salts on plasma Ca concentrations of hypocalcemic periparturient cows and found that oral Ca treatment could treat mild cases of hypocalcemia. We also caution that CaCl2 use must be limited because excessive amounts cause severe metabolic acidosis.