The Pharmacodynamics of Ascorbic Acid in Cattle. I. Absorption and Elimination

It has been believed generally that cattle syntheuize sufficient quantities of aseorbie acid to meet their requirements. Several investigators Others (9, 21, Whitnah and Riddell (35) and Riddell et al. (22) fed 65 kg. of green rye to dairy cows which were otherwise kept under barn feeding conditions. They observed several-fold increase in the urinary excretion of ascorbie acid and a doubling of the blood plasma levels during the first 12 hours. The blood plasma and urinary ascorbie acid returned to pre-feeding levels within 24 hours. No significant changes occurred in the milk aseorbie acid as a result of feeding green rye.