Dietary influences on sodium and potassium metabolism of reindeer

Abstract

Sodium (Na) and potassium (K) concentrations in plasma, saliva, rumen liquor, urine, and feces were measured in reindeer, Rangifer tarandus, given diets high in Na and K (a commercial livestock ration), low in both minerals (lichens), and low in Na and high in K (summer range in interior Alaska). Sodium concentrations in plasma, urine, feces, and saliva were high in reindeer fed the commercial ration and were lower in reindeer grazing summer vegetation. Concentrations of Na and K in saliva were highly correlated with those in plasma. During summer, there was a decrease in saliva Na and an increase in K. The calculated salivary Na:K ratio for reindeer grazing summer vegetation (1.4:1 and 1.6:1) suggested Na insufficiency. Sodium concentrations were higher and within the normal range in saliva of reindeer fed lichens.