Rate of Absorption of Carotene and of Vitamin A from the Alimentary Tract of Dairy Calves. I. Effect of Method of Administration

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Abstract
Carotene and vit. A given at the rate of 1000 I. U. per lb. body wt. were administered, respectively, by nipple feeder, stomach tube and gelatin capsule. Comparisons of initial blood plasma carotenoid and vit. A levels with those 2, 4, 8, 12 and 24 hrs. after feeding the vit. A substances were employed as criteria of the rates of absorption. Carotene and vit A dispersed in milk by homogenization and fed by nipple were absorbed more rapidly than similar prepns. administered by stomach tube. The rates of absorption from carotene and vit. A concentrates administered by gelatin capsules were somewhat less rapid than those resulting from the foregoing procedures. The rate of absorption of vit. A by calves restricted to a whole milk diet was less rapid than that by the same calves after having received a diet of reconstituted buttermilk, grain concentrates and hay for approx. 8 wks. Conversely, the rate of absorption of carotene was more rapid under the former dietary regime than under the latter.