The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat production

This review explores the potential of including glutamine, a so-called non-essential amino acid, in the formulation of reduced-crude protein (CP) diets for broiler chickens. There is a precedent for benefits when including glycine and serine in reduced-CP diets. Fundamentally this is due to decrease...

Full description

Saved in:
Bibliographic Details
Main Authors: Peter H. Selle, Shemil P. Macelline, Mehdi Toghyani, Sonia Yun Liu
Format: Article
Language:English
Published: KeAi Communications Co., Ltd. 2024-09-01
Series:Animal Nutrition
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2405654524000659
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850210039925571584
author Peter H. Selle
Shemil P. Macelline
Mehdi Toghyani
Sonia Yun Liu
author_facet Peter H. Selle
Shemil P. Macelline
Mehdi Toghyani
Sonia Yun Liu
author_sort Peter H. Selle
collection DOAJ
description This review explores the potential of including glutamine, a so-called non-essential amino acid, in the formulation of reduced-crude protein (CP) diets for broiler chickens. There is a precedent for benefits when including glycine and serine in reduced-CP diets. Fundamentally this is due to decreases in non-essential amino acid concentrations in reduced-CP diets — an unavoidable consequence of reducing CP without amino acid supplementation. The situation for glutamine is complicated because analysed dietary concentrations are very rarely provided as standard assays do not differentiate between glutamine and glutamate and are reported on a combined basis as glutamic acid. The dietary requirement for glutamic acid is approximately 36.3 g/kg but it is increasingly unlikely that this requirement will be met as dietary CP levels are progressively reduced. Glutamine is an abundant and versatile amino acid and constitutes 50.5 mg/g of whole-body chicken protein and is the dominant free amino acid in systemic plasma where it has been shown to provide 22.6% (139.9 of 620.3 μg/mL) of the total in birds offered 215 g/kg CP, wheat-based diets. In addition to dietary intakes, glutamine biosynthesis is derived mainly from the condensation of glutamate and ammonia (NH3) catalysed by glutamine synthetase, a reaction that is pivotal to NH3 detoxification. Glutamate and NH3 are converted to glutamine by phosphate-dependent glutaminase in the reciprocal reaction; thus, glutamine and glutamate are interchangeable amino acids. However, the rate of glutamine biosynthesis may not be adequate in rapidly growing broiler chickens and exogenous and endogenous glutamine levels are probably insufficient in birds offered reduced-CP diets. The many functional roles of glutamine, including NH3 detoxification and maintenance of acid-base homeostasis, then become relevant. Twenty feeding studies were identified where dietary glutamine supplementation, usually 10 g/kg, was evaluated in birds kept under thermoneutral conditions. On balance, the outcomes were positive, but the average dietary CP was 213 g/kg across the twenty feeding studies, which indicates that CP and, in turn, glutamine concentrations would have been adequate. This suggests that glutamine inclusions in reduced-CP diets hold potential and consideration is given to how this may be best confirmed.
format Article
id doaj-art-7685e90e2ffb4612838fc6456a4aa498
institution OA Journals
issn 2405-6545
language English
publishDate 2024-09-01
publisher KeAi Communications Co., Ltd.
record_format Article
series Animal Nutrition
spelling doaj-art-7685e90e2ffb4612838fc6456a4aa4982025-08-20T02:09:52ZengKeAi Communications Co., Ltd.Animal Nutrition2405-65452024-09-0118495610.1016/j.aninu.2024.03.017The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat productionPeter H. Selle0Shemil P. Macelline1Mehdi Toghyani2Sonia Yun Liu3Poultry Research Foundation within the University of Sydney, Camden, NSW 2570, Australia; Sydney School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia; Corresponding author.Poultry Research Foundation within the University of Sydney, Camden, NSW 2570, Australia; School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camden, NSW 2570, AustraliaPoultry Research Foundation within the University of Sydney, Camden, NSW 2570, Australia; School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camden, NSW 2570, AustraliaPoultry Research Foundation within the University of Sydney, Camden, NSW 2570, Australia; School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camden, NSW 2570, AustraliaThis review explores the potential of including glutamine, a so-called non-essential amino acid, in the formulation of reduced-crude protein (CP) diets for broiler chickens. There is a precedent for benefits when including glycine and serine in reduced-CP diets. Fundamentally this is due to decreases in non-essential amino acid concentrations in reduced-CP diets — an unavoidable consequence of reducing CP without amino acid supplementation. The situation for glutamine is complicated because analysed dietary concentrations are very rarely provided as standard assays do not differentiate between glutamine and glutamate and are reported on a combined basis as glutamic acid. The dietary requirement for glutamic acid is approximately 36.3 g/kg but it is increasingly unlikely that this requirement will be met as dietary CP levels are progressively reduced. Glutamine is an abundant and versatile amino acid and constitutes 50.5 mg/g of whole-body chicken protein and is the dominant free amino acid in systemic plasma where it has been shown to provide 22.6% (139.9 of 620.3 μg/mL) of the total in birds offered 215 g/kg CP, wheat-based diets. In addition to dietary intakes, glutamine biosynthesis is derived mainly from the condensation of glutamate and ammonia (NH3) catalysed by glutamine synthetase, a reaction that is pivotal to NH3 detoxification. Glutamate and NH3 are converted to glutamine by phosphate-dependent glutaminase in the reciprocal reaction; thus, glutamine and glutamate are interchangeable amino acids. However, the rate of glutamine biosynthesis may not be adequate in rapidly growing broiler chickens and exogenous and endogenous glutamine levels are probably insufficient in birds offered reduced-CP diets. The many functional roles of glutamine, including NH3 detoxification and maintenance of acid-base homeostasis, then become relevant. Twenty feeding studies were identified where dietary glutamine supplementation, usually 10 g/kg, was evaluated in birds kept under thermoneutral conditions. On balance, the outcomes were positive, but the average dietary CP was 213 g/kg across the twenty feeding studies, which indicates that CP and, in turn, glutamine concentrations would have been adequate. This suggests that glutamine inclusions in reduced-CP diets hold potential and consideration is given to how this may be best confirmed.http://www.sciencedirect.com/science/article/pii/S2405654524000659Broiler chickenGlutamateGlutamic acidGlutamine
spellingShingle Peter H. Selle
Shemil P. Macelline
Mehdi Toghyani
Sonia Yun Liu
The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat production
Animal Nutrition
Broiler chicken
Glutamate
Glutamic acid
Glutamine
title The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat production
title_full The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat production
title_fullStr The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat production
title_full_unstemmed The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat production
title_short The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat production
title_sort potential of glutamine supplementation in reduced crude protein diets for chicken meat production
topic Broiler chicken
Glutamate
Glutamic acid
Glutamine
url http://www.sciencedirect.com/science/article/pii/S2405654524000659
work_keys_str_mv AT peterhselle thepotentialofglutaminesupplementationinreducedcrudeproteindietsforchickenmeatproduction
AT shemilpmacelline thepotentialofglutaminesupplementationinreducedcrudeproteindietsforchickenmeatproduction
AT mehditoghyani thepotentialofglutaminesupplementationinreducedcrudeproteindietsforchickenmeatproduction
AT soniayunliu thepotentialofglutaminesupplementationinreducedcrudeproteindietsforchickenmeatproduction
AT peterhselle potentialofglutaminesupplementationinreducedcrudeproteindietsforchickenmeatproduction
AT shemilpmacelline potentialofglutaminesupplementationinreducedcrudeproteindietsforchickenmeatproduction
AT mehditoghyani potentialofglutaminesupplementationinreducedcrudeproteindietsforchickenmeatproduction
AT soniayunliu potentialofglutaminesupplementationinreducedcrudeproteindietsforchickenmeatproduction