Utilization of Intravenously Administered Carotene by Dairy Calves

Abstract

Due to the inconsistent results of experiments with cattle on the utilization of intravenously injected carotene, 12 male dairy calves were fed a low-carotene diet until their plasma vitamin A level was less than 5 γ per 100 ml., or until outward changes of avitaminosis A were established. Nine of these calves were given intravenously carotene suspended in an aqueous solution of Tween 40 at rates from 1 to 24 mg. per 100 lb. of live weight for periods up to 68 days. Utilization of the injected carotene was indicated by reversal or lowered incidence of vitamin A deficiency changes, such as nyctalopia, diarrhea, and muscular incoordination. Several calves receiving the carotene injections were maintained on the basal ration for periods from 180 to 336 days. In contrast, uninjected calves died within about 100 days. Following injections, there was a marked increase in plasma carotene with moderate but irregular increases in plasma vitamin A. Bile of injected calves exhibited an orange color, whereas uninjected calves’ bile had a characteristic green color. Bile from the former calves did not prevent avitaminosis A when fed to rats. © 1959, American Dairy Science Association. All rights reserved.