The copper, iron and lead contents of a series of livers from normal foetal and new-born lambs

Abstract

The copper, iron and lead contents were determined on an age series of foetal livers obtained during the latter half of pregnancy from normal ewes at Cambridge. The total amounts of the metals showed a rapid rise during the last 3 weeks of gestation due to an increase in the size of the organ and in the actual concentrations. Towards full term and in the new-born animal the results showed an increasing variation which even extended to twins. It is noted that foetal transference takes place without affecting the blood copper of the ewe or causing a physiological anaemia of pregnancy. The time at which the process is at its height is correlated with experience in the prophylaxis of swayback. It is estimated that the store of copper at birth may tide the lamb through the suckling period but the store of iron requires to be supplemented by the diet and that the ewe's milk may make a significant contribution towards this. The small amounts of lead found were of the same order as reported for normal humans and in swayback lambs in Derbyshire; hence the latter cannot be regarded as abnormal.