|
|
||||||||
ANIMAL NUTRITION |



* ARS, USDA, U.S. Meat Animal Research Center, Clay Center, NE 68933,
and
ARS, USDA, Swine Odor and Manure Management Research Unit, National Swine Research and Information Center, Ames, IA 50011,
and
University of Illinois, Urbana 61801 and
and
University of Nebraska, Lincoln 68583
2 Correspondence: P.O. Box 166 (phone: 402-762-4206; fax: 402-762-4209; e-mail: jtyen{at}email.marc.usda.gov).
Abstract
Net portal absorption of AA during the 6-h postprandial period was measured in eight gilts (48.5 ± 1.6 kg BW) in a crossover design. The pigs had chronic catheters placed in the portal vein, carotid artery, and ileal vein, and were trained to consume 1.2 kg of a standard grower diet once daily. Blood samples were taken every 30 min for 4 h and then hourly until 6 h after feeding. The first set of blood samples was taken after pigs were fed a meal of the test 16% CP cornsoybean meal diet (16% CP) or the test 12% CP cornsoybean meal diet supplemented with crystalline lysine, threonine, and tryptophan (12% CP + AA) to equal the three AA levels in the 16% CP diet. Pigs were then fed the standard diet for 2 d. Following that, blood samples were again taken after the pigs were fed a meal of the test diet that was not given to them at the first sampling period. Net portal AA absorption was calculated by multiplying porto-arterial plasma AA concentration difference by portal vein plasma flow rate (PVPF), estimated by an indicator-dilution technique employing p-aminohippuric acid as the indicator infused into the ileal vein. Plasma concentrations of lysine and threonine of pigs were affected by the diet x time interaction (P < 0.01). Portal and arterial plasma lysine and threonine concentrations in pigs attained the maximal level by 1 h postprandial when the 12% CP + AA diet was fed, but reached the peak level at 2.5 h postprandial when the 16% CP diet was given. The PVPF of pigs over the 6 h postprandial was less (P < 0.01) when the 12% CP + AA diet was given than when the 16% CP diet was fed. Net portal absorptions of lysine and threonine also were affected (P < 0.05) by time x diet interaction. The peak portal absorption of both lysine and threonine in pigs appeared at 0.5 h postprandial when the 12% CP + AA diet was given, but at 2.5 h postprandial with the feeding of the 16% CP diet. The early appearance of peak portal absorption of lysine and threonine from feeding the 12% CP + AA compared with the 16% CP diet indicates that crystalline lysine and threonine are absorbed more rapidly than protein-bound lysine and threonine in pigs fed once daily.
Key Words: Crystalline Amino Acids Lysine Pigs Portal Absorption Protein-Bound Amino Acids Threonine
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] |
||||
![]() |
F. Guay, S. M. Donovan, and N. L. Trottier Biochemical and morphological developments are partially impaired in intestinal mucosa from growing pigs fed reduced-protein diets supplemented with crystalline amino acids J Anim Sci, July 1, 2006; 84(7): 1749 - 1760. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. W. Dean, L. L. Southern, B. J. Kerr, and T. D. Bidner Isoleucine requirement of 80- to 120-kilogram barrows fed corn-soybean meal or corn-blood cell diets J Anim Sci, November 1, 2005; 83(11): 2543 - 2553. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |