QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Brown, J. A. Articles by Cline, T. R. Search for Related Content PubMed PubMed Citation Articles by Brown, J. A. Articles by Cline, T. R.

Urea Excretion in the Pig: an Indicator of Protein Quality and Amino Acid Requirements¹

Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907

Urinary urea excretion of pigs fed diets differing in amino acid adequacy was measured. Supplementation of a corn diet known to be first limiting in lysine with L-lysine resulted in a significant decrease in total urinary urea excretion as compared with pigs fed the same diet without supplemental lysine. This difference was maximal by day 3 after introduction of the two diets. When graded levels of lysine were added to the diet, urinary urea excretion decreased linearly. The quadratic effect approached significance. Similar results were obtained when graded levels of tryptophan were added to a diet known to be first limiting in tryptophan. The addition of the first limiting amino acid to the pig's diet also resulted in a decrease of plasma urea levels, but this measurement proved to be less precise than the urinary urea excretion. These data suggest that total urinary excretion levels can be used as an indicator of protein quality and possibly to assess the amino acid requirements of swine and other nonruminant animals.

KEY WORDS: • urea excretion • amino acid requirements

¹ Contribution from the Department of Animal Sciences. Journal Paper no. 5178, Purdue University Agricultural Experiment Station.

Manuscript received 5 July 1973.

This article has been cited by other articles:

				J. Klindt, R. M. Thallman, and T. Wise Effects of sire line, sire, and sex on plasma urea nitrogen, body weight, and backfat thickness in offspring of Duroc and Landrace boars J Anim Sci, June 1, 2006; 84(6): 1323 - 1330. [Abstract] [Full Text] [PDF]

				S. Zervas and R. T. Zijlstra Effects of dietary protein and oathull fiber on nitrogen excretion patterns and postprandial plasma urea profiles in grower pigs J Anim Sci, December 1, 2002; 80(12): 3238 - 3246. [Abstract] [Full Text] [PDF]

				S. Zervas and R. T. Zijlstra Effects of dietary protein and fermentable fiber on nitrogen excretion patterns and plasma urea in grower pigs J Anim Sci, December 1, 2002; 80(12): 3247 - 3256. [Abstract] [Full Text] [PDF]