PARTIAL REPLACEMENT OF SKIM MILK WITH FREE AMINO ACIDS IN DIETS FOR THE PIGLET

1984 ◽  
Vol 64 (4) ◽  
pp. 1019-1022 ◽  
Author(s):  
R. O. BALL ◽  
K. I. KIM ◽  
H. S. BAYLEY
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Control Diet ◽  
Skim Milk ◽  
Partial Replacement ◽  
Synthetic Diet ◽  
Acid Diet ◽  
Amino Acid Requirements

A semi-synthetic diet in which 60% of the nitrogen from dried skim milk was replaced with a mixture of free amino acids supported gains of 236 g/day between 3 and 18 days of age, as compared with a gain of 282 g/day for a control diet in which skim milk provided all the protein. Neutralizing the acidity of the free amino acid diet increased its palatability. All of the indispensible amino acids may be made deficient in the experimental diet, thus providing the opportunity to evaluate the amino acid requirements of the piglet. Key words: Piglets, growth, amino acids, semi-synthetic diet

scholarly journals Oxidation of an indicator amino acid by young pigs receiving diets with varying levels of lysine or threonine, and an assessment of amino acid requirements

1983 ◽  
Vol 50 (2) ◽  
pp. 391-399 ◽  
Author(s):  
Kyu-Il Kim ◽  
James I. Elliott ◽  
Henry S. Bayley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Skim Milk ◽  
Linear Increase ◽  
Single Amino Acid ◽  
Dietary Level ◽  
Dietary Amino Acids ◽  
Young Pigs ◽  
Amino Acid Requirements

1. The catabolism of [14C]phenylalanine was used to indicate the effects of varying the dietary level of lysine and threonine on the retention of dietary amino acids by 2-week-old pigs receiving diets containing skim milk and a mixture of free amino acids.2. Reducing the dietary level of lysine from 16 to 12 g/kg had no influence on phenylalanine oxidation, reducing the lysine level from 12 to 11 then to 10 g/kg caused an almost linear increase in phenylalanine oxidation whereas further reduction to 9 or 8 g/kg resulted in a less-marked increase in phenylalanine oxidation. This showed that 12 g lysine/kg was required to maximize amino acid retention and indicated that lysine was conserved more effectively at low dietary concentrations than at dietary concentrations approaching the requirement.3. Reducing the dietary level of threonine from 8 to 6 g/kg had no influence on phenylalanine oxidation, whereas further reduction to 4 g/kg caused a linear increase in phenylalanine catabolism showing that 6 g threonine/kg was required to maximize amino acid retention.4. Reduction of the levels of lysine, threonine and methionine from the generous levels characteristic of a diet containing 240 g protein from skim milk/kg, to the requirement levels determined separately in the presence of the generous levels of all the other amino acids, resulted in a twofold increase in phenylalanine catabolism. This shows that the pig seems able to conserve limiting intakes of a single amino acid, but not if the intakes of two or three amino acids are limiting.

scholarly journals Metabolism of heat-damaged proteins in the rat

1971 ◽  
Vol 26 (2) ◽  
pp. 311-322 ◽  
Author(s):  
J. E. Ford ◽  
C. Shorrock
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Total Amino Acid ◽  
Carbohydrate Complex ◽  
Urinary Peptide

1. Freeze-dried cod muscle and casein were subjected to various conditions of heat treat-ment. Diets containing the different products, or the unheated materials, were given to a group of four adult male rats during successive 48 h periods, and urine was collected during the second 24 h of each 48 h period. A further collection of urine was made from the rats after they had been given protein isolated from heated skim-milk powder. The content and amino acid composition of the ‘peptide’ and ‘free amino acids’ in the urines were determined.2. Heat damage to the cod-fillet protein increased the total urinary excretion of peptide-bound amino acids, from 18·6 to 48·8 µmol/rat.d. The composition of the peptide also changed, and in particular there was a marked increase in lysine, from 2·98 to 20·30 µmol %. Three amino acids - lysine, aspartic acid and glutamic acid - together comprised nearly 70 % of the total amino acid residues. There was a corresponding increase in urinary excretion of free amino acids, from 53·7 to I 14·4 µmol/rat.d. The combined losses of lysine in urinary peptide and free amino acids were 1·5 % of the total lysine ingested, as against 0·3 % for the unheated cod fillet.3. The effects of similar heat treatment of casein on the composition of the urinary peptide and free amino acids were less marked. There was no increase in total urinary peptide excretion and there was a smaller increase in the lysine content of the peptide.4. In urine of rats given protein isolated from heated skim-milk powder, the peptide hydro-lysate was rich in lysine and in furosine, which together comprised 41 mol % of the total amino acid composition. These compounds were presumably formed, together with a smaller quantity of pyridosine, from lysine-carbohydrate complex in the urine. It is probable that, as compared with free lysine, the lysine-carbohydrate complex was absorbed relatively in-efficiently from the rat intestine.5. The findings are discussed in relation to the wider question of the metabolism of the ‚unavailable peptide’ that is released in the course of digestion of heat-damaged protein.

scholarly journals Influence of dietary protein concentration on the oxidation of phenylalanine by the young pig

1986 ◽  
Vol 55 (3) ◽  
pp. 651-658 ◽  
Author(s):  
Ronald O. Ball ◽  
Henry S. Bayley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
G Protein ◽  
Dietary Protein ◽  
Free Amino Acids ◽  
Free Amino ◽  
Crude Protein ◽  
Protein Concentration ◽  
Skim Milk ◽  
Intact Protein

1. Piglets were weaned at 3 d of age and reared to 2.5 kg on a liquid diet in which the protein was supplied by dried skim milk and a mixture of free amino acids. The oxidation of L-[l-14C]phenyIalanine was measured as an indication of the partition of amino acids between retention and catabolism in pigs (2.5 kg) offered meals containing vaned concentrations of crude protein (nitrogen x 6.25).2. The dietary protein concentration was varied either by increasing the inclusion of a mixture of free amino acids in a series of diets containing 100 g protein/kg from skim milk, or by increasing the level of inclusion of the skim milk in a series of diets containing the equivalent of 100 g protein/kg from the free amino acid mixture.3. The oxidation of phenylalanine was minimized by dietary protein concentrations of 240 and 258 g/kg for the diets containing increasing concentrations of free amino acids or skim milk respectively.4. These results show that a mixture of free amino acids is used more effectively than intact protein for promoting retention of essential amino acids.5. The recovery of radioactivity in expired carbon dioxide was inversely related to the recovery of radioactivity in liver tissue when the concentration of dietary crude protein was increased from deficient to adequate, demonstrating that the fractional oxidation of the indicator amino acid was inversely related to protein synthesis.

scholarly journals Amino acid oxidation by young pigs receiving diets with varying levels of sulphur amino acids

1983 ◽  
Vol 50 (2) ◽  
pp. 383-390 ◽  
Author(s):  
Kyu-Il Kim ◽  
Henry S. Bayley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Choline Chloride ◽  
Milk Powder ◽  
Skim Milk ◽  
Essential Amino Acids ◽  
Acid Oxidation ◽  
Amino Acid Requirement

1. Piglets were weaned at 3 d of age and were introduced to liquid diets in which 400 g/kg protein was supplied as skim-milk powder and the balance as a mixture of free amino acids. The skim milk contributed 2·3 g methionine and 1·4 g cystine/kg diet; the experimental diets were made by supplementing these levels with free amino acids.2. The adequacy of the test level of the amino acid in the diet was assessed by measuring the oxidation of [1−14]phenylalanine as an indicator of the partition of the essential amino acids between incorporation into protein and degradation. Radioactivity recovered as carbon dioxide was used as a measure of catabolism.3. Addition of 0·2, 0·4, 0·7, 1·2 and 1·7 g L-methione/kg to a diet containing 5 g cystine and 3 g choline chloride/kg showed that phenylalanine catabolism was minimal for the diet with 2·7 g methionine/kg indicating that this is the dietary requirement for methionine to serve as a source of methionine residues for protein synthesis.4. Addition of D-methionine to produce a series of diets with graded levels of methionine showed that the D-isomer was less effective than the L-isomer in reducing phenylalanine catabolism: the addition of 0·8 g D-methionine/kg diet was needed to produce the same effect as 0·4 g L-methionine/kg diet showing that the replacement value of D-methionine for L-methionine was 50% in the young pig.5. To investigate the influence of cystine on methionine requirement, diets with varying levels of methionine and cystine were prepared. Oxidation of [U-14C]methionine was used as an indication of an excess of methionine, and the results showed that increasing the dietary methionine level above 3·0 g/kg in diets containing 1·4 g cystine/kg provided an excess of methionine for oxidation. This indicated a sulphur amino acid requirement of 4·4 g/kg, one-third of this being supplied as cystine.

scholarly journals Determination of amino acid requirements of young pigs using an indicator amino acid

1983 ◽  
Vol 50 (2) ◽  
pp. 369-382 ◽  
Author(s):  
Kyu-Il Kim ◽  
Ian McMillan ◽  
Henry S. Bayley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Essential Amino Acid ◽  
Free Amino ◽  
Skim Milk ◽  
Linear Increase ◽  
Deficient Diet ◽  
Direct Estimate ◽  
Phenylalanine Level

1. Mixtures of skim milk and free amino acids were compared as diets for pigs which would allow manipulation of dietary amino acid levels. Piglets gained 208 g/d between 3 and 14 d of age on the skim-milk diet, but replacement of 600 g/kg of the dietary nitrogen with free amino acids reduced growth rate to 148 g/d.2. Supplementation of a lysine-deficient diet with lysine reduced the catabolism of [14C]phenylalanine showing that phenylalanine catabolism could be used as an indicator of the adequacy of diet with respect to another essential amino acid.3. The dietary level of phenylalanine which would provide an excess for catabolism by the piglet was estimated directly by measuring the influence of dietary phenylalanine level on [14C]phenylalanine oxidation. Reduction of the dietary phenylalanine level below 7 g/kg had no effect on phenylalanine oxidation, whereas increasing the dietary phenylalanine level above 7 g/kg resulted in a linear increase in phenylalanine oxidation.4. An indirect estimate of histidine requirement was made by examining the influence of dietary histidine level on [14C]phenylalanine oxidation. In diets containing more than 4 g histidine/kg, phenylalanine oxidation was minimal. In diets containing less than 4 g histidine/kg, [14C]phenylalanine oxidation increased as the level of dietary histidine was reduced. This showed that the utilization of the essential amino acid phenylalanine, for protein synthesis, was not limited by histidine supply in diets containing more than 4 g histidine/kg.5. A direct estimate of histidine requirement was made by examining the influence of dietary histidine level on [14C]histidine oxidation. Diets with more than 4 g histidine/kg contained an excess which was catabolized: there was a linear increase in histidine oxidation in response to dietary histidine levels greater than 4 g/kg. This confirmed the previous indirect estimate of histidine requirement.

scholarly journals Changes in the plasma concentrations of free amino acids in relation to egg formation in the hen

1970 ◽  
Vol 24 (4) ◽  
pp. 1071-1081 ◽  
Author(s):  
T. G. Taylor ◽  
J. J. Waring ◽  
R. K. Scougall
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Egg Production ◽  
Nutritive Value ◽  
Plasma Concentrations ◽  
Essential Amino Acids ◽  
Egg Formation ◽  
Amino Acid Requirements

1. The changes occurring in the free amino acids of the plasma of laying hens in relation to egg formation have been investigated in fed and starved hens in three experiments, each with eight birds.2. The mean concentrations of most amino acids and of the totals were higher at night than in the morning.3. In general, egg formation was associated with increases in the concentrations of non- essential and decreases in the concentrations of essential amino acids. Cystine and glutamic acid tended to behave like the essential amino acids.4. After 40 h starvation seven amino acids, particularly serine, histidine and lysine, in- creased in concentration and only three, proline, ornithine and arginine, decreased significantly.5. When eight cocks were injected with oestrogen most of the amino acids increased in con-centration. The essential amino acids (with the exception of phenylalanine), serine, proline, cystine and ornithine showed the greatest increases.6. The results are discussed in relation to the possibility that the voluntary food intake of hens may be influenced by changes in the plasma levels of one or more essential amino acids associated with the synthesis of egg albumen. Arginine appeared to be the only amino acid that might possibly fulfil this role.7. It was concluded that investigations of changes in the free amino acids of hen plasma are unlikely to provide a useful approach to a study of the amino acid requirements or the nutritive value of particular proteins for egg production.

The amino acid requirements of the rediae of Cryptocotyle lingua and Himasthla leptosoma and of the sporocyst of Cercaria emasculans Pelseneer, 1900

Parasitology ◽  
1970 ◽  
Vol 61 (3) ◽  
pp. 491-496 ◽  
Author(s):  
Stuart D. M. Watts
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Food Sources ◽  
Amino Acid Requirement ◽  
Molar Ratios ◽  
Amino Acid Requirements ◽  
Free Amino Acid Pools

Few workers have studied the amino acid requirement of larval Digenea in vivo. Cheng (1963) conducted a study of three species of parasites, each from a different host, and suggested that both free and bound host amino acids act as food sources. His assumptions are based on the disappearance of free amino acids from the sera of infected molluscs and the qualitative similarities between parasite and host with respect to both free and bound amino acids. Negus (1968), working on Turritella communis infected with the sporocysts of Cercaria doricha, described an almost identical qualitative composition of both the free amino acid pools and the hydrolysates of host gonad and parasite tissue. He was of the opinion that this was not coincidental. Considerable quantitative similarities between the free amino acids were also evident. Read, Rothman & Simmons (1963), in discussing cestode metabolism and membrane transport, proposed that it is the molar ratios of amino acids in the host which are important to the parasite and that the amino acid requirement may be more subtle than a simple need for certain components. Indeed, they suggest that this may form one basis for physiological host specificity.

Biochemische Aspekte des Aminosäuren-Stoffwechsels bei Psoriasis vulgaris / Biochemical Aspects of Amino Acid Metabolism in Psoriasis vulgaris

1973 ◽  
Vol 28 (7-8) ◽  
pp. 449-451 ◽  
Author(s):  
G. Peter ◽  
H. Angst ◽  
U. Koch
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Psoriasis Vulgaris ◽  
Normal Subjects ◽  
Pathological Process

Free and protein-bound amino acids in serum and scales were investigated. In serum the bound amino acids of psoriatics are significantly higher with exception of Pro, Met, Tyr and Phe in contrast to normal subjects. For free amino acids the differences between normal subjects and psoriatics found in serum and scales are not significant. Results are discussed in relation to the single amino acids and the biochemical correlations are outlined which takes the pathological process as a basis.

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