[Variations in plasma ferritin during the transition from immature hens to mature ones in relation to laying].

The mobilization of iron stores during the transit from non laying to laying hen has been studied. A series of parameters related to iron metabolism (hemoglobin, hematocrit, plasma iron, transport iron binding capacity and plasma ferritin) have been determined during six consecutive weeks in which the setting percentage increased from 0 to 83%. Five male samples had been previously estrogenized to obtain a quick answer for the same parameters determined in the females. A decrease in plasma ferritin levels has been observed in both experiments, suggesting a mobilization of iron stores to the egg especially during the two weeks in which the setting percentage increase was highest (16-60%).