Comparison of Oral Sodium Compounds for the Correction of Acidosis

¹ Department of Animal Science, Iowa State University, Ames 50011
² USDA, Agricultural Research Service, National Animal Disease Center, Metabolic Diseases and Immunology Research Unit, Ames, IA 50010-0070

Three Na compounds were tested to determine which was best able to treat metabolic acidosis in dairy cows. Metabolic acidosis was induced in test cows by feeding a diet that was high in anions for 7 d before the administration of treatment on d 8. The orally administered treatments were equivalent amounts of Na in the form of NaCl (208.6 g), NaHCO₃ (300 g), or Na propionate (343 g). The initiation of oral treatment was designated as time 0, and blood samples were taken 15 min before treatment, immediately before treatment, and 15, 30, 45, 60, 90, 120, 180, 240, 300, and 360 min after treatment. Before treatment, all cows were in a state of metabolic acidosis as was evidenced by low blood pH, low HCO₃ concentrations, and high plasma Cl concentrations. After treatment, blood pH and HCO₃ were markedly higher for cows receiving NaHCO₃ and Na propionate but not for cows receiving NaCl. We concluded that orally administered NaHCO₃ and Na propionate were equally effective in correcting the acid-base balance of blood, as was predicted by the strong ion difference theory of acid-base physiology. Sodium propionate may be considered a more effective treatment of metabolic acidosis in diseases such as ketosis because the added propionate can serve as a source of glucose for the cow.

Key Words: acid-base status • sodium propionate • acidosis

Submitted on April 23, 1996
Accepted on April 8, 1997