Vitamin C Content of Market Milk, Evaporated Milk, and Powdered Whole Milk

Abstract
The rate of depletion of initially large hepatic reserves of vitamin A and carotene is given for 140 steers over an experimental period of 166 days. The animals were divided into two dietary groups. One group was on a fattening ration low in carotene and the other on a maintenance ration relatively high in carotene. The rate of depletion of the hepatic reserves of vitamin-A and carotene decreased as the liver reserves of the two constituents decreased. No clinical evidence of avitaminosis A was observed in any of the animals throughout the experimental period. This would indicate the possibility of extremely low levels of vitamin A reserve in cattle without producing symptoms of avitaminosis A. Hepatic reserves of vitamin A were found to be more readily depleted than were hepatic reserves of carotene. Increasing values were found for the ratio of the liver with increasing carotene reserves of the liver. It was found that hepatic reserves of carotene are maintained in cattle in direct proportion to the carotene intake. An increasing rate of loss of hepatic reserves of vitamin A occurred with decreasing carotene intake.