Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1991-9-17
pubmed:abstractText
A dose response procedure was developed for evaluating vitamin A status and utilization in cattle. This could be useful for evaluating diets, vitamin A stores and homeostatic control of vitamin A. Three experiments were designed to determine: 1) size of vitamin A dose required to increase plasma vitamin A concentrations; 2) time after dosing when plasma vitamin A concentrations peak, and 3) if changes in plasma vitamin A concentrations are useful in assessing dietary vitamin A utilization. Using twenty-four steers and heifers, the first two experiments showed that 30X or 40X daily vitamin A requirement (daily requirement calculated as X = body weight in kilograms times 55 International Units of vitamin A) given orally was sufficient to cause plasma vitamin A concentrations to rise 20 hours after dosing. Plasma vitamin A concentrations increased (P less than .01) from 57 to 81 micrograms/dl and 64 to 84 micrograms/dl after a 30X or 40X treatment, respectively. Twenty-X daily requirement resulted in a slight increase after 20 hours (P greater than .05). Seventy-two feedlot steers were used in experiment three to determine if diet affects vitamin A dose response. Variations in feed intake, monensin in the diet or a single dose of vitamin E did not cause significant changes in plasma vitamin A response to vitamin A dosage. Steers receiving monensin had higher initial plasma vitamin A concentrations, but no differences were observed after dosing. Results indicate that dose responses may be useful in assessing dietary vitamin A utilization.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0300-9831
pubmed:author
pubmed:issnType
Print
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
314-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Plasma vitamin A levels in cattle in response to large doses of vitamin A.
pubmed:affiliation
Department of Animal Science, University of Kentucky, Lexington 40546.
pubmed:publicationType
Journal Article