Subdividing Amino Acid Requirements into Portions for Maintenance and Growth

THE AMINO ACID REQUIREMENTS OF MAN

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)81430-8 ◽

1955 ◽

Vol 216 (2) ◽

pp. 763-773

Author(s):

William C. Rose ◽

Robert L. Wixom

Keyword(s):

Amino Acid ◽

Amino Acid Requirements

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THE AMINO ACID REQUIREMENTS OF MAN

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)57159-9 ◽

1955 ◽

Vol 217 (1) ◽

pp. 95-101

Author(s):

William C. Rose ◽

Robert L. Wixom

Keyword(s):

Amino Acid ◽

Amino Acid Requirements

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THE AMINO ACID REQUIREMENTS OF MAN

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)71332-x ◽

1954 ◽

Vol 206 (1) ◽

pp. 421-430 ◽

Cited By ~ 2

Author(s):

William C. Rose ◽

William J. Haines ◽

Donald T. Warner

Keyword(s):

Amino Acid ◽

Amino Acid Requirements

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PSXI-31 Program Chair Poster Pick: Determination of the threonine requirement in adult and senior Labrador Retrievers using the indicator amino acid oxidation technique

Journal of Animal Science ◽

10.1093/jas/skaa278.574 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 321-322

Author(s):

Jordan T Weil ◽

Jessica L Varney ◽

Jason W Fowler ◽

Craig N Coon

Keyword(s):

Amino Acid ◽

Control Diet ◽

Genetic Selection ◽

Isotope Ratio Mass Spectrometry ◽

Acid Oxidation ◽

Amino Acid Oxidation ◽

Amino Acid Requirements ◽

Indispensable Amino Acids ◽

Nutrient Profiles ◽

Labrador Retrievers

Abstract Although nutrient profiles for canines have been developed in the past, the need to update amino acid (AA) requirements has gained importance as genetic selection changes the recommended nutrients. Correctly feeding AA to canines can have enormous effects, considering a deficiency or excess of such nutrient can lead to weight loss, disease, or in some cases, death. Amino acid requirements can be determined through the nitrogen balance or indicator amino acid oxidation (IAAO) methods. In this experiment, the IAAO technique was used to determine the threonine (Thr) requirement in Labrador retrievers. A total of six dogs (6 adult and 6 senior) were subjected to six diets with varying levels of Thr, ranging from deficient to excess. Diets were formulated to 1.6x NRC values for all indispensable amino acids. The control diet was fed for two days, followed by a day in which the test diet was fed, a tracer AA was supplied, and breath samples were collected. On test day, a priming dose of L-[1-13C]phenylalanine (Cambridge Isotope Laboratories, Inc.) based on the subject’s body weight was first supplied, followed by [1-13C]Phe doses every thirty minutes, spanning a four hour period. A respiration mask was placed on each subject every thirty minutes (Oxymax, Columbus Instruments), 13CO2 was collected, and enrichment was determined by isotope ratio mass spectrometry (IRMS). Results for IRMS were converted to atom percent excess (APE) and analyzed using a piecewise model of best fit (JMP® Pro 15). The segmented line regression showed that the Thr mean and population requirements were determined to be 1.21 ± 0.24 and 0.92 ± 0.17 g/1000kcal (mean ± 2SD) for adult and senior dogs, respectively. As the pet food industry becomes more specialized in diets relating to aging, and diseased canines, updating the amino acid requirements related to such animals is increasingly important.

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Effect of Intraduodenal Starch Infusion on Net Portal Absorption of Amino Acids in Growing steers Fed Lucerne

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600025800 ◽

1994 ◽

Vol 1994 ◽

pp. 28-28

Author(s):

C.J. Seal ◽

D.S. Parker ◽

J.C. MacRae ◽

G.E. Lobley

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Gastrointestinal Tract ◽

Protein Turnover ◽

Portal Blood ◽

Intestinal Lumen ◽

Short Term ◽

Net Uptake ◽

Amino Acid Requirements ◽

Glucose Availability

Amino acid requirements for energy metabolism and protein turnover within the gastrointestinal tract are substantial and may be met from luminal and arterial pools of amino acids. Several studies have demonstrated that the quantity of amino acids appearing in the portal blood does not balance apparent disappearance from the intestinal lumen and that changing diet or the availability of energy-yielding substrates to the gut tissues may influence the uptake of amino acids into the portal blood (Seal & Reynolds, 1993). For example, increased net absorption of amino acids was observed in animals receiving exogenous intraruminal propionate (Seal & Parker, 1991) and this was accompanied by changes in glucose utilisation by the gut tissues. In contrast, there was no apparent change in net uptake of [l-13C]-leucine into the portal vein of sheep receiving short term intraduodenal infusions of glucose (Piccioli Cappelli et al, 1993). This experiment was designed to further investigate the effects on amino acid absorption of changing glucose availability to the gut with short term (seven hours) or prolonged (three days) exposure to starch infused directly into the duodenum.

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