Journal of Dairy Science Vol. 28 No. 6 495-506
© 1945 by American Dairy Science Association ®
The Relationship between a Low Carotene Intake and Urinary Excretion of Ascorbic Acid in Dairy Cattle*
L. A. Moore and
J. W. Cotter
Dairy Department, University of Maryland
ABSTRACT
- typeAscorbic acid excretion in normally fed heifers varied from 25.8 to 110.5 mg. per day.
- When fed 5 grams of chlorobutanol for 10 days normally fed heifers excreted 210 to 399 mg. of ascorbic acid per day.
- Ascorbic acid excretion of pregnant heifers receiving a ration low in carotene was from 4 to 6 times greater than in similar animals normally fed.
- The feeding of 5 grams of chlorobutanol for 10 days to pregnant heifers receiving a ration low in carotene stimulated the excretion of ascorbic acid very little.
- The chlorobutanol caused an increase in plasma ascorbic acid values of the normally fed pregnant heifers but not in similar heifers receiving a low carotene ration.
- Dairy males excreted varying amounts of ascorbic acid regardless of the level of carotene intake, except when made severely deficient, in which case there was a decrease in ascorbic acid excretion.
- Normally fed males excreted considerably more ascorbic acid per kilo of body weight than normally fed females.
- It still remains to be shown that a low carotene intake under practical farm conditions has a depressing effect on ascorbic acid synthesis to the extent of altering breeding efficiency.
FOOTNOTES
* Scientific Paper No. A94, Contribution No. 1953, of the Maryland Agricultural Experiment Station (Department of Dairy Husbandry).
Copyright © 1945 by the American Dairy Science Association ®.