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

This Article Full Text Full Text (PDF) 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 Zervas, S. Articles by Zijlstra, R. T. Search for Related Content PubMed PubMed Citation Articles by Zervas, S. Articles by Zijlstra, R. T.

Effects of dietary protein and oathull fiber on nitrogen excretion patterns and postprandial plasma urea profiles in grower pigs^1,2

S. Zervas^*, and R. T. Zijlstra^*,3

^* Prairie Swine Centre Inc., Saskatoon, SK, Canada S7H 5N9 and and Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada S7N 5A8

³ Correspondence:
P.O. Box 21057, 2105 8th St. E. (phone: 306-373-9922; fax: 306-955-2510; E-mail:
ruurd{at}sask.usask.ca).

The objectives of this study were: 1) to determine if dietary protein reduction or oathull fiber inclusion would reduce urinary N excretion in grower pigs, 2) to determine if plasma urea could predict urinary N excretion among diets differing in protein and fiber content with an expected range in N excretion patterns, and 3) to determine the postprandial time point to sample blood for the best prediction. Three dietary protein concentrations (high, 19.7; medium, 16.9; low, 13.8%) and two fiber levels (high, 5.0; low, 3.6% crude fiber) were tested in a 3 x 2 factorial arrangement. Diets (wheat, barley, soybean meal; oathulls as fiber source) were formulated to 3.25 Mcal of digestible energy (DE)/kg and 2.2 g of digestible lysine/Mcal DE for low- and medium-protein diets, and 2.4 g/Mcal of DE for high-protein diets, and supplemented with lysine, methionine, tryptophan, threonine, isoleucine, or valine to meet an ideal amino acid profile. Pigs (32 ± 3.4 kg; n = 42) were housed in metabolism crates for 19 d. On d 10 or 11, catheters were installed by cranial vena cava venipuncture. Daily feeding allowance was adjusted to 3x maintenance (3 x 110 kcal DE/kg body weight^0.75), and was fed in two equal meals. Feces and urine were collected from d 15 to 19. Five blood samples were collected in 2-h intervals on d 16 and 19. Fecal, urinary, and total N excretion was reduced linearly with a reduction of dietary protein (P < 0.001); the reduction was greater for urinary (48%) and total N excretion (40%) than for fecal N excretion (23%). Similarly, the ratio of urinary to fecal N was reduced linearly with a reduction of dietary protein (P < 0.001). Retention of N (g/d) was reduced linearly, but N retention as a percentage of N intake was increased linearly with a reduction of dietary protein (P < 0.001). The addition of oathulls did not affect N excretion patterns and plasma urea (P > 0.10). Dietary treatments did not affect average daily gain or feed efficiency (P > 0.10). A dietary protein x time interaction affected plasma urea (P < 0.001). For medium- and high-protein diets, plasma urea increased postprandially, peaking 4 h after feeding, and then decreased toward preprandial levels (P < 0.05). Plasma urea did not alter postprandially for the low-protein diet (P > 0.10). Urinary N excretion (g/d) was predicted by 3.03 + 2.14 x plasma urea concentration (mmol/L) at 4 h after feeding (R² = 0.66). Plasma urea concentration is indicative of daily urinary N excretion and reduction of dietary protein is effective to reduce total and urinary N excretion.

Key Words: Excretion • Fibers • Nitrogen • Pigs • Protein • Urea

This article has been cited by other articles:

				F. Guay and N. L. Trottier Muscle growth and plasma concentrations of amino acids, insulin-like growth factor-I, and insulin in growing pigs fed reduced-protein diets J Anim Sci, November 1, 2006; 84(11): 3010 - 3019. [Abstract] [Full Text] [PDF]

				D. M. Panetta, W. J. Powers, H. Xin, B. J. Kerr, and K. J. Stalder Nitrogen excretion and ammonia emissions from pigs fed modified diets. J. Environ. Qual., July 1, 2006; 35(4): 1297 - 1308. [Abstract] [Full Text] [PDF]

				R. A. Kohn, M. M. Dinneen, and E. Russek-Cohen Using blood urea nitrogen to predict nitrogen excretion and efficiency of nitrogen utilization in cattle, sheep, goats, horses, pigs, and rats J Anim Sci, April 1, 2005; 83(4): 879 - 889. [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]