Total Yellow Pigment Research Articles

Utilization of Vitamin A by Turkey Poults I. Crystalline Carotene, Crystalline Vitamin A Acetate and “Black Cod” Liver Oil

The comparative utilization of carotene and of two forms of vitamin A by turkey poults up to 8 weeks of age was studied in two series of feeding tests. Gain in body weight and the amount of vitamin A present in the liver were employed as indices of utilization. Vitamin A in the blood plasma and yellow pigments in both liver and blood plasma were also determined. The results of these studies permit the following conclusions: 1.On the basis of International Units of vitamin A activity, “Black Cod” liver oil, lot B-16487, was found to be approximately twice, and crystalline vitamin A acetate approximately 4 times, as efficient in supporting normal growth in poults as the corresponding levels of crystalline carotene.2.At intakes higher than those required to support normal growth much more vitamin A was stored in the liver when either crystalline vitamin A acetate or “Black Cod” liver oil was fed than when the diet contained corresponding levels of crystalline carotene.3.Poults which received crystalline vitamin A acetate had about twice as much vitamin A in the blood plasma as those which received corresponding levels of crystalline carotene.4.Yellow pigments in the livers and in the blood plasma of poults were found to be high at hatching but decreased rapidly during the first two weeks of life.5.High intakes of crystalline vitamin A acetate were found to depress the total yellow pigments in the liver and to a greater extent those in the blood plasma. On the basis of International Units of vitamin A activity, “Black Cod” liver oil, lot B-16487, was found to be approximately twice, and crystalline vitamin A acetate approximately 4 times, as efficient in supporting normal growth in poults as the corresponding levels of crystalline carotene. At intakes higher than those required to support normal growth much more vitamin A was stored in the liver when either crystalline vitamin A acetate or “Black Cod” liver oil was fed than when the diet contained corresponding levels of crystalline carotene. Poults which received crystalline vitamin A acetate had about twice as much vitamin A in the blood plasma as those which received corresponding levels of crystalline carotene. Yellow pigments in the livers and in the blood plasma of poults were found to be high at hatching but decreased rapidly during the first two weeks of life. High intakes of crystalline vitamin A acetate were found to depress the total yellow pigments in the liver and to a greater extent those in the blood plasma.