Blood Serum and Tissue Free Amino Acid Concentrations of Gilts Fed Dl- Or L-Methionine

Abstract

A semipurified ration containing 0.55% ormethionine was fed to two gilts from each of two litters. and 0.557o L-methionine was fed to an additional two gilts from each litter.Duodenal, liver, and serum methionine levels were higher when nr-methionine was fed, in-

Growth and liver enzyme response in growing rats to graded levels of methionine and cystine in fortified-barley diets: Response at constant cystine concentration in the diet

“…Most published estimates of the methionine plus cystine requirements of the growing rat and the growing pig have been based on either growth and nitrogen balance results (Byington, Howe & Clark, 1972;Sowers, Stockland & Meade, 1972;Braude & Esnaola, 1973;Stockland, Meade, Wass & Sowers, 1973;Brown & Cline, 1974) or serum and plasma amino acid levels (Byington & Howe, 1972;Keith, Christensen & Owen, 1972;Knipfel, Owen & Christensen, 1972;Keith, Peace, Botting & Hamilton, 1975). There has been very little research (Benevenga, 1974;Finkelstein, 1974) into whether enzymes associated with the methionine metabolic pathway could be utilized in assessing the optimal requirements for methionine plus cystine.…”