scholarly journals Endogenous flow of amino acids in the avian ileum as influenced by increasing dietary peptide concentrations

2008 ◽  
Vol 101 (6) ◽  
pp. 822-828 ◽  
Author(s):  
Velmurugu Ravindran ◽  
Patrick C. H. Morel ◽  
Shane M. Rutherfurd ◽  
Donald V. Thomas

The aim of the present study was to establish whether feeding broiler chickens with diets containing increasing dietary peptide concentrations would cause increases in ileal endogenous amino acid flow. The flow of N and most amino acids increased quadratically (P < 0·05 to 0·001) with increasing dietary concentrations of peptides. The exceptions were the flow of threonine, serine, glycine, tyrosine and cystine, which increased linearly (P < 0·001) with dietary peptide levels. Another notable exception to the general trend was the flow of proline, which was significantly higher (P < 0·01) in birds fed the protein-free diet. The amino acid profile of endogenous protein, expressed as proportion of crude protein, indicated that the ratios of threonine, glutamic acid, proline, glycine, leucine, histidine, arginine and cystine were influenced (P < 0·05) with increasing dietary peptide concentrations. In general, compared with the protein-free diet, the ratios of threonine and arginine in endogenous protein were lower (P < 0·05) and those of glutamic acid, glycine and histidine were greater (P < 0·05) in diets with high concentrations of peptides. The ratio of proline was found to decrease (P < 0·05) with increasing dietary peptide concentrations. These changes in the amino acid profile of endogenous protein are probably reflective of changes in the output of one or more of the components of endogenous protein. Overall, the present results demonstrated that increasing dietary peptide concentrations increased the flow of endogenous amino acid flow at the terminal ileum of broiler chickens in a dose-dependent manner and also caused changes in the composition of endogenous protein. The observed changes in endogenous amino flow will influence the maintenance requirements for amino acids and also have implications for the calculation of true digestibility coefficient of feedstuffs.

2004 ◽  
Vol 92 (2) ◽  
pp. 217-223 ◽  
Author(s):  
V. Ravindran ◽  
L. I. Hew ◽  
G. Ravindran

The aim of the present study was to compare the protein-free diet, guanidinated casein (GuC) and enzyme hydrolysed casein (EHC) methods for the quantification of endogenous amino acid (AA) flow in the avian ileum. Growing broiler chickens (5 weeks old) were used. All three assay diets were based on dextrose, and in the GuC and EHC diets GuC or EHC were the sole source of N. Endogenous AA flows determined with the use of protein-free diet were considerably lower (P>0·05) than those determined by the GuC and EHC methods. The total endogenous AA flows determined by the GuC and EHC methods were almost 3-fold greater (P>0·05) than those determined by the protein-free diet. The endogenous AA values obtained from GuC and EHC methods were similar (P<0·05), except for the flow of arginine, which was lower (P>0·05) in the EHC method. Glutamic acid, aspartic acid, threonine and glycine were the predominant endogenous AA present in digesta from the distal ileum. The contents of methionine, histidine and cystine were lower compared with other AA. The method of determination had no effect on the AA composition of endogenous protein, except for threonine, glutamic acid, lysine, arginine and cystine. The concentrations of threonine and arginine were lower (P>0·05) and that of lysine was higher (P>0·05) with the EHC method compared with the other two methods. The concentration of glutamic acid was greater (P0·05) and that of cystine was lower (P>0·05) in the EHC and GuC methods compared with the protein-free diet method. The results showed that the ileal endogenous flows of N and AA are markedly enhanced by the presence of protein and peptides, above those determined following feeding of a protein-free diet. It is concluded that the use of EHC and GuC methods enables the measurement of ileal endogenous losses in chickens under normal physiological conditions.


2004 ◽  
Vol 79 (2) ◽  
pp. 265-271 ◽  
Author(s):  
V. Ravindran ◽  
W. H. Hendriks

AbstractEndogenous flows of nitrogen and amino acids at the terminal ileum of broilers (6 weeks old), layers (70 weeks old) and adult roosters (70 weeks old) were determined using the peptide alimentation method. The ileal endogenous output of nitrogen and total amino acids in broilers, layers and roosters, expressed as mg/kg dry matter intake, were similar (F > 0-05). Endogenous flows were similar (F > 0-05) for nine of the 17 amino acids analysed, but the flows of serine, glutamic acid, proline, alanine, isoleucine, tyrosine, arginine and methionine differed (P < 0-05) among the classes of chickens. The amino acid profile of endogenous protein, expressed asg/100 g crude protein, did not differ (F > 0-05) between the three classes of chickens, except for serine, glutamic acid, proline and isoleucine. The concentrations of proline were higher (F < 0-05) in broilers, compared with the other two groups. The concentrations of glutamic acid in layers were lower (F < 0-05) than the other two groups. The concentrations of serine and isoleucine were higher (F < 0-05) in roosters than the other two groups. In all three groups, the most abundant amino acid in the ileal endogenous protein was glutamic acid, followed by aspartic acid, proline, serine, glycine and threonine. The present study provides estimates for endogenous amino acid flow at the terminal ileum in broilers, layers and adult roosters under normal physiological conditions.


2004 ◽  
Vol 55 (6) ◽  
pp. 705 ◽  
Author(s):  
V. Ravindran ◽  
W. H. Hendriks

The recovery and composition of endogenous protein at the terminal ileum of broiler chickens were determined at 14 and 42 days post-hatching using the peptide alimentation method. The ileal endogenous flows of nitrogen and amino acids, expressed as mg/kg dry matter intake, differed (P < 0.05–0.01) between the two age groups, with flows increasing with age, except for lysine, histidine and glycine. The flows of lysine and histidine were unaffected (P > 0.05) by age, whereas a tendency (P = 0.07) for increased loss with age was observed for glycine. The amino acid profile of ileal endogenous protein, expressed as g/100 g crude protein, did not differ (P > 0.05) between 14-day- and 42-day-old broilers, suggesting that the relative proportions of the individual sources that contribute to the endogenous protein were similar at both ages. In both age groups, the most abundant amino acids in the ileal endogenous protein were glutamic acid, aspartic acid, proline, serine, glycine, and threonine. The present findings suggest that, when determining true digestibility, corrections using endogenous amino acid flows determined with broilers of a particular age to apparent amino acid digestibility values determined with birds of a different age would clearly result in less accurate true digestibility estimates.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1637
Author(s):  
Quintino Reis de Araujo ◽  
Guilherme Amorim Homem de Abreu Loureiro ◽  
Cid Edson Mendonça Póvoas ◽  
Douglas Steinmacher ◽  
Stephane Sacramento de Almeida ◽  
...  

Free amino acids in cacao beans are important precursors to the aroma and flavor of chocolate. In this research, we used inferential and explanatory statistical techniques to verify the effect of different edaphic crop conditions on the free amino acid profile of PH-16 dry cacao beans. The decreasing order of free amino acids in PH-16 dry cacao beans is leucine, phenylalanine, glutamic acid, alanine, asparagine, tyrosine, gamma-aminobutyric acid, valine, isoleucine, glutamine, lysine, aspartic acid, serine, tryptophan, threonine, glycine. With the exception of lysine, no other free amino acid showed a significant difference between means of different edaphic conditions under the ANOVA F-test. The hydrophobic free amino acids provided the largest contribution to the explained variance with 58.01% of the first dimension of the principal component analysis. Glutamic acid stands out in the second dimension with 13.09%. Due to the stability of the biochemical profile of free amino acids in this clonal variety, it is recommended that cacao producers consider the genotype as the primary source of variation in the quality of cacao beans and ultimately the chocolate to be produced.


2000 ◽  
Vol 83 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Vincent Hess ◽  
Philippe Ganier ◽  
Jean-Noel Thibault ◽  
Bernard Sève

The aims of the present study were first to compare the amino acid dilution method performed using labelled animals with that using labelled diets, and second to determine real digestibilities and total ileal endogenous losses of N and amino acids. Two diets containing pea cultivars (Solara and Amino) and a protein-free diet were compared in a 3 × 3 Latin-square experiment. The three pigs were each prepared with an ileo-rectal anastomosis and were continuously infused with [1-13C]leucine. For each cultivar,15N-labelled and unlabelled diets were formulated. The real digestibility and endogenous losses of leucine were higher when obtained by labelling the pig than by labelling the foodstuff. This was due either to the inadequate estimation of the endogenous protein enrichment in the first case or to the importance of dietary N recycling in the second case. However, in both cases the ileal endogenous losses of N and amino acids were higher than the basal losses determined with the protein-free diet. There were significant differences between the two pea cultivars in terms of phenylalanine and leucine when measured with labelled diets. It is suggested that, although ileal endogenous losses may be underestimated, using labelled feedstuffs is of great interest due to the direct estimation of the individual amounts of amino acids.


1999 ◽  
Vol 50 (7) ◽  
pp. 1159 ◽  
Author(s):  
V. Ravindran ◽  
L. I. Hew ◽  
G. Ravindran ◽  
R. J. Gill ◽  
P. H. Pittolo ◽  
...  

A commercial xylanase product was assessed for its effects on the performance of, and apparent metabolisable energy (AME) and ileal amino acid digestibility in, 3 commercial broiler strains (Strain A, B, and C) fed on a diet containing wheat (407 g/kg) and oats (78 g/kg). Exogenous xylanase improved weight gains (P = 0.07) and feed/gain (P < 0.04) of broilers, irrespective of genotype. Performance parameters significantly differed among the broiler strains. Strains A and C consumed more (P < 0.04) feed, and grew faster (P < 0.01) and more efficiently (P = 0.07) than Strain B. Enzyme supplementation resulted in 2.8% improvement (P < 0.05) in the AME of the wheat-based diet. The AME tended to be higher (P = 0.09) with Strain A (13.46 MJ/kg dry matter) and Strain C (13.57 MJ/kg dry matter) than with Strain B (13.10 MJ/kg dry matter). The apparent ileal digestibility of all amino acids was 1–2 percentage units higher in birds fed on the enzyme-supplemented diet than in those fed on the unsupplemented diet (controls), but the differences were significant (P < 0.05) only for threonine, methionine, isoleucine, arginine, aspartic acid, serine, and glutamic acid. Highly significant (P < 0.001) strain effects were observed for apparent ileal digestibility of all amino acids, with Strain A recording the highest (0.807–0.945) and Strain B the lowest (0.710–0.912). Mean ileal digestibility coefficients of the 15 amino acids in wheat-based diets for Strains A, B, and C were 0.858, 0.791, and 0.828, respectively. Ileal digesta viscosity was low, and was not affected by dietary enzyme, suggesting that other factors were responsible for the observed improvements in bird performance.


2020 ◽  
Vol 12 (1) ◽  
pp. 11-19
Author(s):  
Olawale Paul Olatidoye ◽  
Taofik Akinyemi Shittu ◽  
Samuel Olusegun Anwonorin ◽  
Emmanuel Sunday Akin Ajisegiri

Cashew kernels are one of the most concentrated food products due to their fat and protein content and they are used in puddings and bakery products, hence the determination of their protein quality is an important nutritional factor in dietary protein requirements. Therefore, the study aimed at evaluating the effect of roasting conditions on the protein quality of cashew kernels at the temperature of 100–160 °C and time (20–60 min), and then analysing for the amino acid profile by GC-FID; protein predicted efficiency ratio (P-PER), essential amino acid index (EAAI), and the Isoelectric point (pI). About 2.0 kg of dried cashew kernels used were defatted using chloroform/methanol (2:1/v/v) as the extraction solvent and then analysed using standard methods. The results showed that seventeen amino acids were present in cashew nuts, where glutamic acid (15.27g/100gN); aspartic acid (12.20g/100gN); lysine (6.09g/100g N), and phenylalanine (5.06g/100g N) were predominant. Eight essential amino acids were present in cashew kernels, the highest value of 7.33g/100g were for lysine (6.09g/100gN); 1.70g/100gN (histidine); 3.42g/100gN (threonine); 3.63g/100gN (valine); 3.57 g/100gN (isoleucine); 7.33g/100gN (leucine); and 5.06g/100gN (phenylalanine). Roasting reduced the lysine content by 18.4%, phenylalanine by 12.06%, and aspartic acid by 41.4% at 160°C for 60 min, while serine (58.9%); glutamic acid (19.7%); arginine (47.4%), and histidine (115.9%) were increased, suggesting that cashew nuts contain high quality protein. P-PER results were 2.57 (raw), 171-2.61 (roasted); EAAI is 1.55(raw) and 1.38-1.55 (roasted), BV% is 76.15 (raw) and 67.61-76.89 (roasted); the Isoelectric points were 4.65 (raw) and 3.87- 4.54 (roasted), The Leu/Ileu ratio was 2.12 (raw) and 2.01-2.67 (roasted). It was concluded that the heat treatment used does not significantly affect the amino acid profile of cashew kernels, thus preserving their nutritional quality.


1998 ◽  
Vol 67 (1) ◽  
pp. 131-138 ◽  
Author(s):  
M. Reverter ◽  
J. E. Lindberg

AbstractIleal digestibility of amino acids in barley-based diets with increasing inclusion of lucerne leaf meal (LLM; 0, 50, 100 and 200 g/kg) was studied in a change-over experiment with post-valve T-caecum cannulated growing pigs. The apparent Heal digestibility of crude protein, as well as of most of the essential (EAA) and non-essential amino acids (NEAA) was not significantly affected by the dietary inclusion of LLM. The exceptions were cystine, methionine, phenylalanine, glutamic acid and serine, all of which showed a significant (P< 0·05) reduction in apparent Heal digestibility with increasing inclusion of LLM. In contrast, the calculated true Heal digestibility of all EAA (with the exception of arginine and lysine) and the NEAA glutamic acid and serine were significantly (P< 0·05) reduced with the inclusion of LLM. Associated with an increased crude protein intake, there was a significant (P< 0·05) increase in the amount of absorbed EAA when the proportion of LLM was increased in the diet. With increasing proportion of fibre in the diet, there was a significant (P< 0·05) increase in the Heal flow of glucosamine.It can be concluded from the present data that the inclusion of LLM in a barley-based diet for growing pigs will result in an improvement in the absorbed amino-acid profile due to a significant increase in the absorption of all of the EAA.


1957 ◽  
Vol 3 (7) ◽  
pp. 967-974 ◽  
Author(s):  
J. M. McLaughlan

Cystine, cysteinesulphinic acid (CSA), and other closely related sulphur-containing amino acids inhibited growth of Escherichia coli 113-3, particularly in aerobic conditions. The cystine inhibition was completely prevented by aspartic acid, partially reversed by pantothenic acid or β-alanine and slightly reversed by lysine or thiamine. The inhibitory effect of CSA was completely or partially reversed by aspartic acid, lysine, glutamic acid, proline, ornithine, or homoserine. Aspartic acid and glutamic acid appeared to reverse the inhibition competitively while lysine seemed to reverse the inhibition in a noncompetitive manner. Reversal of the inhibitory effect of relatively high concentrations of CSA by lysine was not complete, however, unless methionine was also present. Possible mechanisms of the cystine and CSA inhibition are discussed.


2015 ◽  
Vol 11 (4) ◽  
pp. 201-212 ◽  
Author(s):  
R.H. Dunstan ◽  
D.L. Sparkes ◽  
B.J. Dascombe ◽  
C.A. Evans ◽  
M.M. Macdonald ◽  
...  

Little is known about the amino acid composition of horse sweat, but significant fluid losses can occur during exercise with the potential to facilitate substantial nutrient losses. Sweat and plasma amino acid compositions for Standardbred horses were assessed to determine losses during a standardised training regime. Two cohorts of horses 2013 (n=5) and 2014 (n=6) were assessed to determine baseline levels of plasma and sweat amino acids. An amino acid supplement designed to counter losses in sweat during exercise was provided after morning exercise daily for 5 weeks (2013, n=5; 2014, n=4). After the supplementation period, blood and sweat samples were collected to assess amino acid composition changes. From baseline assessments of sweat in both cohorts, it was found that serine, glutamic acid, histidine and phenylalanine were present at up to 9 times the corresponding plasma concentrations and aspartic acid at 0-2.2 μmol/l in plasma was measured at 154-262 μmol/l in sweat. In contrast, glutamine, asparagine, methionine and cystine were conserved in the plasma by having lower concentrations in the sweat. The predominant plasma amino acids were glycine, glutamine, alanine, valine, serine, lysine and leucine. As the sweat amino acid profile did not simply reflect plasma composition, it was proposed that mechanisms exist to generate high concentrations of certain amino acids in sweat whilst selectively preventing the loss of others. The estimated amino acid load in 16 l of circulating plasma was 3.8-4.3 g and the calculated loss via sweat during high intensity exercise was 1.6-3.0 g. Following supplementation, total plasma amino acid levels from both cohorts increased from initial levels of 2,293 and 2,044 µmol/l to post-supplementation levels of 2,674 and 2,663 µmol/l respectively (P<0.05). It was concluded that the strategy of providing free amino acids immediately after exercise resulted in raising resting plasma amino acid levels.


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