The amounts of vitamin A aldehyde, esters and alcohol and of carotenoids in hen's eggs and in day-old chicks

In the ripe eggs of several species of marine and freshwater teleost fish, the predominant form of vitamin A is the aldehyde (Plack & Kon, 1961 ; Plack, Woodhead & Woodhead, 1961). Vitamin A aldehyde has also been found in the megalecithal eggs of other vertebrates, and in particular in those of the domestic hen (Plack, 1960; Plack & Kon, 1961). Since the aldehyde may be of importance in embryonic development, the amounts of vitamin A aldehyde in eggs and in day-old chicks have been compared, and it has been found that only 16 % of the aldehyde assumed to be present originally in the egg is present in the day-old chick. Results for vitamin A esters and alcohol and for carotenoids are also given, though similar results have been reported previously (Parrish, Williams, Hughes & Payne, 1950; Parrish, Williams & Sanford, 1951). The effect of 21 days’ incubation on the vitamin A and carotenoid contents of infertile eggs was also studied.