Iron metabolism in the laying hen

Abstract

Determinations of egg and plasma Fe over a whole season in 15 birds showed a great elevation of plasma Fe just before laying commenced. The high level persisted during the period of regular laying, and there was a high [image] correlation (r = 0.717, P<0.001) between mean plasma Fe and mean egg Fe. Total blood Fe determinations over the same period suggested that in many hens the onset of laying is preceded by a fall in blood hemoglobin. The lower level persists during the period of regular laying. Determinations of total and non-hem Fe in liver, spleen and kidney over the short period during which hens were coming into lay suggested that there may perhaps be a slight decrease in non-hem Fe in the liver at this time, but that the quantity involved is small compared to that utilized for the eggs in the same period. It is concluded that the demand for Fe for the eggs must be met by an increase in the efficiency of Fe absorption.