Holstein calves, partially depleted of vitamin A stores, were daily fed 12 to 540 7 of carotene per lb. live weight and/or 2.0 to 69..5 7 of vitamin A for either 12 or 16 wk. Hereford steers from native grass pasture were fed 5.8 to 116.0 7 of vitamin A for 40 wk. Vitamin A depletion time was more s...