Effect of a Dietary Lysine Deficiency on the Concentration of Amino Acids in the Deproteinized Blood Plasma of Chicks

Abstract

A lysine-deficient basal diet, both with and without supplemental lysine added, was fed to groups of Barred Plymouth Iiock cockerels from hatching to 4 weeks of age. .4t this time blood sanlples were taken from the carotid artery and pooled for each group. Twelve amino acids were determined in the deproteinized plasma by microbiological assay. Deproteinized plasma from birds receiving the lysine-deficient diet was lower in lysine content and higher in threonine and tyrosine than that from birds fed the lysine-supplemented diet. Other amino acids showed milch smaller differences. A similar amino acid pattern was observed when the birds were fed the lysine-supplemented diet for 25 days from hatching and then the lysine-deficient diet for 3 days before blood samples were taken. Withholding feed for 24 hours before the samples were taken resulted in a marked increase in Iysine and threonine concentration, an effect which has been reported by other workers. Acid hydrolysis of the deproteinized plasma increased somewhat the concentration of lysine, as measured microbiologically, bt!t had no effect on, or solnewhat reduced, the concentrations of other a~nino ac~ds.

Effects of Moderate Lysine Deficiency on Digestibility and Metabolisable Energy of Diets and on Nitrogen Retention and Uric Acid Excretion in Chicks

“…This is in agreement with the results of Gray et al (1960) and by Hewitt (1966), as reported by Lewis (1967).…”

The Effect of Dietary Diammonium Citrate on Glutamine and Glutamic Acid Concentration in the Blood Plasma of Chicks

“…The preparation of the protein-free plasma and the method for the determination of glutamic acid and glutamine have been described in previous papers (Gray et al, 1960;Olsen et ah, 1962). Heparin was used as an anticoagulant.…”

Conditions Affecting Plasma Amino Acid Patterns in Chickens Fed Practical and Purified Diets

“…Direct application of this method failed to predict limiting amino acids when the chick was used as a test animal (Smith and Scott, 1965a, b;Dean and Scott, 1966). Difficulty in application of this method with the chick resulted mainly from the considerable elevation of concentrations of lysine and threonine that occur during starvation (Gray et al, 1960). The extent of the elevation in the concentrations of amino acids varies among species (Shao and Hill, 1967;Boomgaardt and Mc-Donald, 1969).…”