Interorgan Metabolism, Nutritional Impacts, and Safety of Dietary L-Glutamate and L-Glutamine in Poultry

Molecular and metabolic responses to immune stress in the jejunum of broiler chickens: transcriptomic and metabolomic analysis

“…β-alanine is a direct synthetic precursor of pantothenic acid (vitamin B5) and an indispensable intracellular component of the intermediate metabolites’ coenzyme A and acyl carrier protein ( Wang et al, 2021 ). Glutamine and glutamate, as abundant amino acids in poultry ( He et al, 2021 ), are important components in the synthesis of glutathione ( Watanabe et al, 2021 ), a natural antioxidant that plays an important role in the defence against oxidative stress ( Park, et al, 2020 ). Glutamine and glutamine can produce products such as α-ketoglutarate as well as ammonia and carbon dioxide through carboxylation and deamination reactions.…”

Muscle growth affects the metabolome of the pectoralis major muscle in red-winged tinamou (Rhynchotus rufescens)

“…In addition to these functions, this amino acid is involved in the neural control of feed intake and body weight in birds by influencing the expression of orexigenic (related to appetite) and anorexigenic (related to loss of appetite) neuropeptides in the central nervous system ( Paul et al, 2012 ). Thus, glutamate supplementation has also been used in birds to achieve maximum growth, production, and feed efficiency ( He et al, 2021a ).…”

The “ideal protein” concept is not ideal in animal nutrition

“…Fifth, the “ideal protein” concept ignores the nutritional and physiological needs of the small intestine, the reproductive system, and immunocytes of animals (including pigs, chickens, and fish) for AASAs, which are not only major energy sources for enterocytes but also key regulators of gene expression, gut integrity, spermatogenesis, embryonic survival, immunity, and health. 3,13,29,56,67–69 For example, dietary glutamate, glutamine, glycine, and proline protect the small intestine from oxidative stress and atrophy in weanling pigs, 2,55–57 whereas dietary arginine enhances placental water transport and nitric oxide (NO) synthesis, as well as embryonic and fetal survival in gestating swine. 69–71 Furthermore, a lack of glutamate or glutamine in diets results in high rates of mortality in juvenile hybrid-striped bass.…”

“…However, such a fundamental knowledge had not received much attention from nutritionists until recent years. 3,11,13,26,[29][30][31] The traditional view that animals have no dietary requirements for NEAAs must be refuted in light of the new knowledge of AA biochemistry, nutrition and physiology. The term "NEAAs" has now been recognized as a misnomer in nutritional science 30 and, therefore, should be replaced by AAs that are synthesizable de novo in animal cells (AASAs).…”

“…25,28,68,73 In addition, sufficient dietary glutamate and glutamine are also essential for maximum lean tissue gain in broiler chickens particularly under stress conditions. 26,29 Furthermore, although there have been good progress in the manufacturing of environmentally sustainable, low-CP diets based on the "ideal protein" concept to meet the requirements of swine and poultry for all EAAs, all the attempts without the inclusion of AASAs in diets have not been successful for the maximum growth or productivity of the animals. [76][77][78][79] In view of the foregoing, we suggest that the "ideal protein" concept be replaced with "optimum ratios and amounts of all proteinogenic AAs" for animals.…”