Natural 15N Abundance in Key Amino Acids from Lamb Muscle: Exploring a New Horizon in Diet Authentication and Assessment of Feed Efficiency in Ruminants

2016 ◽  
Vol 64 (20) ◽  
pp. 4058-4067 ◽  
Author(s):  
Gonzalo Cantalapiedra-Hijar ◽  
Isabelle Ortigues-Marty ◽  
Anne-Marie Schiphorst ◽  
Richard J. Robins ◽  
Illa Tea ◽  
...  
Keyword(s):  
Amino Acids ◽  
Feed Efficiency ◽  
Natural 15N Abundance ◽  
15N Abundance

scholarly journals Natural 15N abundance in specific amino acids indicates associations between transamination rates and residual feed intake in beef cattle

2020 ◽  
Vol 98 (6) ◽  
Author(s):  
Gonzalo Cantalapiedra-Hijar ◽  
Pablo Guarnido ◽  
Anne-Marie Schiphorst ◽  
Richard J Robins ◽  
Gilles Renand ◽  
...  
Keyword(s):  
Amino Acids ◽  
Beef Cattle ◽  
Feed Intake ◽  
Genetic Selection ◽  
Residual Feed Intake ◽  
Future Research ◽  
Metabolic Reaction ◽  
Natural 15N Abundance ◽  
Δ 15N ◽  
15N Abundance

Abstract Improving the ability of animals to convert feed resources into food for humans is needed for more sustainable livestock systems. Genetic selection for animals eating less while maintaining their performance (i.e., low residual feed intake [RFI]) appears a smart strategy but its effectiveness relies on high-throughput animal phenotyping. Here, we explored plasma nitrogen (N) isotope ratios in an attempt to identify easily superior young bulls in terms of RFI. For this, 48 Charolais young bulls fed two contrasting diets (corn vs. grass silage diets) were selected from a larger population as extreme RFI animals (24 low-RFI vs. 24 high-RFI) and their plasma analyzed for natural 15N abundance (δ15N) in the whole protein (bulk protein) and in the individual protein-bound amino acids (PbAA). For the first time, we showed that the δ 15N in plasma bulk protein differed (P = 0.007) between efficient (low-RFI) and inefficient (high-RFI) cattle regardless of diet. Furthermore, most analyzed PbAA followed the same trend as the bulk protein, with lower (P < 0.05) δ 15N values in more efficient (low-RFI) compared with less efficient (high-RFI) cattle, again regardless of diet. The only three exceptions were Phe, Met, and Lys (P > 0.05) for which the first metabolic reaction before being catabolized does not involve transamination, a pathway known naturally to enrich AAs in 15N. The contrasted isotopic signatures across RFI groups only in those PbAA undergoing transamination are interpreted as differences in transamination rates and N-use efficiency between low- and high-RFI phenotypes. Natural isotopic N signatures in bulk proteins and specific PbAA can be proposed as biomarkers of RFI in growing beef cattle fed different diets. However, the current study cannot delineate whether this effect only occurs post-absorption or to some extent also in the rumen. Our data support the conclusion that most efficient cattle in terms of RFI upregulate N conservation mechanisms compared with less efficient cattle and justify future research on this topic.

Pattern of natural 15N abundance in lakeside forest ecosystem affected by cormorant-derived nitrogen

2006 ◽  
pp. 69-86 ◽  
Author(s):  
Kayoko Kameda ◽  
Keisuke Koba ◽  
Satoru Hobara ◽  
Takashi Osono ◽  
Masakazu Terai
Keyword(s):  
Forest Ecosystem ◽  
Natural 15N Abundance ◽  
15N Abundance

Natural 15N/14N isotope composition in C3 leaves: are enzymatic isotope effects informative for predicting the 15N-abundance in key metabolites?

2011 ◽  
Vol 38 (1) ◽  
pp. 1 ◽  
Author(s):  
Guillaume Tcherkez
Keyword(s):  
Amino Acids ◽  
Nitrogen Isotopes ◽  
Isotope Composition ◽  
Isotope Effects ◽  
Stomatal Closure ◽  
Metabolic Model ◽  
Organic N ◽  
State Equations ◽  
Leaf Level ◽  
15N Abundance

Although nitrogen isotopes are viewed as important tools for understanding plant N acquisition and allocation, the current interpretation of natural 15N-abundances (δ15N values) is often impaired by substantial variability among individuals or between species. Such variability is likely to stem from the fact that 15N-abundance of assimilated N is not preserved during N metabolism and redistribution within the plant; that is, 14N/15N isotope effects associated with N metabolic reactions are certainly responsible for isotopic shifts between organic-N (amino acids) and absorbed inorganic N (nitrate). Therefore, to gain insights into the metabolic origin of 15N-abundance in plants, the present paper reviews enzymatic isotope effects and integrates them into a metabolic model at the leaf level. Using simple steady-state equations which satisfactorily predict the δ15N value of amino acids, it is shown that the sensitivity of δ15N values to both photorespiratory and N-input (reduction by nitrate reductase) rates is quite high. In other words, the variability in δ15N values observed in nature might originate from subtle changes in metabolic fluxes or environment-driven effects, such as stomatal closure that in turn changes v0, the Rubisco-catalysed oxygenation rate.

scholarly journals Ehrlich chromogens, probable cross-links in elastin and collagen

1988 ◽  
Vol 252 (2) ◽  
pp. 387-393 ◽  
Author(s):  
P D Kemp ◽  
J E Scott
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Absorption Coefficient ◽  
Cross Linking ◽  
Diazonium Salts ◽  
Gel Chromatography ◽  
Skin Collagen ◽  
Cross Links ◽  
End Group ◽  
15N Abundance

(1) Proteolytic digests of tissue elastin contain material which reacts with dimethylaminobenzaldehyde in acid solution (Ehrlich's reagent) to give a cherry-pink colour. This Ehrlich chromogen(s) [EC(s)] is similar to but not identical with EC(s) previously demonstrated in tissue collagens [Scott, Hughes & Shuttleworth (1979) Biosci. Rep. 1, 611-618]. Both ECs react with diazonium salts in acid to give coloured products. (2) Diazobenzene linked via a phenolic ester to polyacrylamide beads (Biogel P10) has been used to absorb ECs specifically and almost quantitatively from proteolytic digests. The coupled deeply coloured azo-EC-peptides were then recovered after mild alkaline cleavage from the support and purified by gel chromatography. (3) Using 15N-labelled NaNO2, the collagen azo-EC-peptides were prepared, and 15N abundance measured therein. The molar absorption coefficient of the azo-EC group was calculated (18,700) based on the assumption that each azo-EC group contained one 15N atom. (4) Collagen azo-EC-peptides contained glucose and galactose, whereas elastin azo-EC peptides did not. The amino acid patterns of the two peptides were quite different, the former being rich in polar amino acids, the latter containing much alanine. The patterns were compatible with an origin from the cross-linking regions of collagen and elastin respectively. (5) Quantitative (molar) comparisons of the azo-EC group content with amino acid, amino end-group and sugar contents, and azo-EC peptide molecular mass, suggest that a structure is present in the collagen azo-EC-peptides containing two EC groups shared between four peptide chains. Three peptide chains probably meet at each (cross-linking) EC group. (6) Based on this structure, about 15% of adult bovine skin collagen contains EC groups.

Effect of different levels of dietary crude protein on the growth performance and carcass characteristics of commercial broilers at different phases of growth

2017 ◽  
Author(s):  
T. Srilatha ◽  
V. Ravinder Reddy ◽  
V. Chinni Preetam ◽  
S.V. Rama Rao ◽  
Y. Ramana Reddy
Keyword(s):  
Amino Acids ◽  
Growth Performance ◽  
Feed Efficiency ◽  
Crude Protein ◽  
Body Weight Gain ◽  
Carcass Characteristics ◽  
Abdominal Fat ◽  
Dietary Crude Protein ◽  
Low Levels ◽  
Different Levels

An experiment was conducted to find out the effect of different levels of crude protein in broiler diets during different phases. i.e., pre starter (0-11d), starter (12-21d) and finisher (22-42d). 360 day-old broilers (Vencobb) were procured from a commercial hatchery and fed either high or low dietary CP diets during pre-starter (23 and 21%) , starter (21 and 19%) and high, moderate or low CP diets during finisher ( 18.5, 17.5 and 16.5%) phases, for a total of 12 possible treatment combinations at d 42. The results showed that the broilers fed low levels of CP ( 21 and 19 %) had significantly(P less than 0.05) higher body weight gain (BWG) and feed intake (FI), and better feed efficiency over the diets with high levels of CP during pre-starter and starter phases (23 and 21%, respectively). The higher (18.5%) level of protein in the finisher phase showed higher BWG and best FCR compared to the lower levels (17.5 and 16.5%). Carcass characters were not influenced by the variation in dietary CP level tested except the abdominal fat weight which was significantly higher in broiler fed low CP diet compared to those fed higher levels of CP during all three phases. The results indicated that the broilers fed low CP diets supplemented with critical amino acids (21 and 19%) had beneficial effect on the growth performance during pre-starter and starter phase. The broilers showed an ability to respond to increase in dietary CP levels during finisher phase.

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