Amino Acid Oxidation and Plasma Amino Acid Levels in Sheep with Abomasal Infusions of Graded Amounts of Lysine2

Publisher Website
Google Scholar
Abstract
The potential of the oxidation technique for estimating the amino acid requirement of the sheep was investigated. A series of seven infusion trials was conducted in which a wether lamb, fed a low protein diet, was made limiting in lysine by the abomasal infusion of a mixture of the essential amino acids devoid of lysine. This limitation was sequentially removed in subsequent trials by the abomasal infusion of graded amounts of lysine. Plasma-free amino acid concentrations and the oxidation of lysine, monitored as expired radioactivity from the oxidation of arterially injected L-lysine-U-14C hydrochloride, were measured in all trials. The production of 14CO2 and the plasma-free lysine concentrations did not markedly increase until a certain level of abomasal lysine supplementation had been attained. This level was estimated to be 2.1 and 2.4 g of supplemental lysine using 14CO2 production and plasma-free lysine levels as response criteria, respectively. The amount of lysine entering the abomasum from the rumen in this experiment was estimated to be 4.4 g per day. Thus, the abomasal lysine requirement for this sheep fed this particular diet and made limiting in lysine was estimated to be 6.5 to 6.8 g per day. The points at which plasma-free amino acid concentrations and carbon dioxide production from an amino acid begin to rapidly increase, provide similar estimates of the lysine requirement of the sheep. Copyright © 1973. American Society of Animal Science . Copyright 1973 by American Society of Animal Science.

This publication has 0 references indexed in Scilit: