Estimation of the Milk Intake of Sucklings by Means of 22Na

Abstract

Pups of dingoes and domestic dogs were injected with 22NaCl and rates of sodium turnover were derived. These rates were highly correlated with rates of milk consumption; however, isotopically based estimates of sodium intake were consistently lower than actual sodium intake by about 20%. Even so, we believe that milk consumption by pups can be estimated reliably using sodium turnover. The advantages of the 22Na turnover technique over tritiated water turnover and gravimetric techniques are discussed.