The Effect of Excessive Amounts of Dietary Vitamin A on Egg Production in White Leghorn Hens

Abstract

ALTHOUGH adequate amounts of vitamin A are necessary for the normal metabolism of animals, and humans, it is well known that excessive quantities of the vitamin can prove harmful. Giroud and Martinet (1954) reported that large amounts of dietary vitamin A adversely affected the reproductive ability of the rat and a similar conclusion was reached by Friend and Crampton (1961) in their studies with mink. During the course of an investigation in these laboratories on cholesterol metabolism in White Leghorn chickens (Wood, Biely and Topliff, 1961) it was observed that the presence of dogfish liver oil in the diet resulted in a cessation of egg production. Since the oil was rich in vitamin A it was thought that perhaps this was due to the massive doses of vitamin A ingested by the birds. The present investigation was carried out to ascertain whether vitamin A did interfere with egg production, and …