The need for vitamin A in the ration of dairy cattle to permit growth as well as other vital function is quite generally recognized. The minimum amount necessary for normal growth in cattle of different ages is probably not so well known. The authors reported in 1932 (1) that calves fed for 20 to 30 days on whole milk from cows on low vitamin A rations and then fed skim milk together with a grain mixture and late-cut brown timothy hay invariably died bef ore 100 days of age—usually from pneumonia. In 1934 (2) and 1936 (3) we reported that calves made about normal gains from birth to 6 months of age on our low vitamin A ration when it was supplemented with 15 milligrams daily of carotene in oil or with 20 cubic centimeters or even 10 cubic centimeters daily of animal feeding cod-liver oil. These supplements seemed sufficient even when skim milk feeding was commenced on the fourth day of age, when the calves had had colostrum for only three days.