VITAMIN A REQUIREMENTS OF GROWING CHICKS: I. PRELIMINARY STUDIES WITH "REFERENCE" COD LIVER OIL

Abstract

In experiments conducted to determine the requirements of chicks for vitamin A up to eight weeks of age, vitamin A was supplied, in addition to the basal ration, by oral administration of Reference Cod Liver Oil at the rate of 25, 50, 75 and 100 International units per day. It was found that chicks receiving 75 units of vitamin A per day grew at a normal rate and did not show any signs of vitamin A deficiency. The chicks that received the basal ration only, showed symptoms of avitaminosis A at three weeks of age, while the group receiving 25 international units per day at eight weeks clearly had not received a sufficient supply of the growth factor.