The transfer of maternal dietary riboflavin to the embryo during development in the common fowl

Abstract

In this paper a detailed examination of the rate of transfer of riboflavin to the embryo during incubation is reported.Confirmatory evidence of the direct effect of egg content of riboflavin on subsequent growth of the chick is supported by liver analyses for riboflavin. Changes in the liver content after hatching show that after 10 days on a low riboflavin diet reserves of chicks reach a minimal level irrespective of original egg content.The data for the rate of transfer of riboflavin to the embryo show a direct relationship between the amount reaching the embryo and the initial content of the egg. Evidence is presented of a large rate of transfer at the most critical period of development, which is at 14–15 days as judged by embryonic mortality in riboflavin deficiency. In eggs containing low levels of the vitamin a relatively small amount of the vitamin reaches the embryo at this critical 15-day stage.The time required for hens on a low dietary level of riboflavin to reach maximal egg levels is shown to be of the order of three weeks.The utilization by the embryo of riboflavin injected into the egg is studied quantitatively. The injected vitamin is as fully utilized by the embryo as is riboflavin deposited at egg formation.Qualitative chromatographic separation of the flavines of fertile eggs during incubation shows a gradual increase in combined forms as development proceeds.