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.