Sulfur Amino Acid Activity of d- and l-Homocysteine for Chicks
- 1 January 1978
- journal article
- research article
- Published by Frontiers Media SA in Experimental Biology and Medicine
- Vol. 157 (1), 139-143
- https://doi.org/10.3181/00379727-157-40008
Abstract
Summary Young male chicks were fed crystalline l-amino acid diets in assays designed to evaluate the capacity of d-and l-homocysteine to supply methionine and cysteine. l-Homocysteine had a cystine-sparing value of 100% and a methio-nine-sparing value of 28% at the level fed. d-Homocysteine was utilized less efficiently than was l-homocysteine, having a cystine-sparing value of 68% and a methionine-sparing value of only 7%. The methionine activity of l-homocysteine varied when evaluated in a cystine-adequate diet, being more efficiently utilized at low levels of intake. However, at every level fed, l-homocysteine was inferior to l-methionine in supporting growth. The presence of additional choline in the diet did not improve the performance of chicks fed l-homocysteine as a source of methionine. Performance of chicks fed dl-homocysteine as a source of total sulfur amino acids was equal to that of chicks fed dl-homocysteine as a source of methionine per se. The utilization of the d and l isomers of homocysteine appears to be limited by the methionine activity they can replace. The results of these assays clearly indicate that young chicks fed a crystalline l-amino acid diet cannot efficiently convert either d- or l-homocysteine to methionine via transmethylation.This publication has 4 references indexed in Scilit:
- The Choline Requirement of Broiler Chicks During the Seventh Week of LifePoultry Science, 1976
- Toxicity of Various Organic Sulfur Compounds for Chicks Fed Crystalline Amino Acid Diets Containing Threonine and Glycine at Their Minimal Dietary Requirements for Maximal GrowthJournal of Animal Science, 1975
- Methionine Replacement Value of N-Acetylmethionine and Homocysteinethiolactone Hydrochloride for Growing RatsJournal of Nutrition, 1975
- Sulfur Utilization by the Chick with Emphasis on the Effect of Inorganic Sulfate on the Cystine-Methionine InterrelationshipJournal of Nutrition, 1974