HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Prior, R. L. Articles by Britton, R. A. Search for Related Content PubMed Articles by Prior, R. L. Articles by Britton, R. A.

Influence of Supplemental Nitrogen Source and Time on Feed on Tissue Serine Concentrations and Enzymes of Serine Synthesis and Degradation in Sheep¹

US Department of Agriculture^,4, Clay Center, Nebraska 68933 and and University of Nebraska, Lincoln 68583

Abstract

A total of 53 wethers were used in two experiments to study the effects of level and source of supplemental nitrogen on the metabolism of serine to glucose and CO₂ and on enzymes involved in serine metabolism. The sheep were fed a basal diet containing wheat straw and corn starch with no supplemental nitrogen (N) or the supplemental N provided by urea or a mixture of corn gluten meal (2/3) and soybean meal (1/3). Activities of liver D-3-phosphoglycerate dehydrogenase (EC 1.1.1.95) and D-glycerate dehydrogenase (EC 1.1.1.29) were not significantly affected by level or source of supplemental N. Liver serine dehydratase (EC 4.2.1.13) was higher in sheep fed no supplemental N compared to those receiving supplemental N. In vitro glucose synthesis from serine by liver slices was increased (P<.05) in urea-fed sheep after 60 days, but not after 48 days on experiment compared to the other dietary treatments. Liver but not muscle serine concentrations were increased in urea-fed sheep after 60 days on experiment compared to those receiving supplemental protein. The enzyme data obtained in this study do not explain the increased liver serine concentrations in urea-fed sheep.

¹ Published as Paper No. 5532, Journal Series, Nebraska Agr. Exp. Stat., Lincoln.

² Roman L. Hruska U.S. Meat Animal Research Center, Agr. Research, Science and Education Administration.

³ Dept. of Animal Science, Univ. of Nebraska, Lincoln 68583.

⁴ Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable.