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.