Broiler diets low in crude protein may get a boost from individual nonessential amino acid supplementation - Interpretive Summary

Thanks for sharing this interesting article. We should stop calling these amino acids "nonessential". They are truly functional amino acids in animal nutrition. For example, in chickens, glutamate and aspartate are major metabolic fuels for enterocytes of the small intestine. In addition, glutamine stimulates protein synthesis and inhibits protein breakdown in chicken skeletal muscle. We now know that glutamine acts through activating multiple cell signaling pathways [e.g., the mechanistic target of rapamycin (MTOR)]. I hope that the following publications will be helpful for our discussions on this important subject matter. Wu, G. and J.R. Thompson. 1990. The effect of glutamine on protein turnover in chick skeletal muscle in vitro. Biochem. J. 265:593-598. Wu, G. 2010. Functional amino acids in growth, reproduction and health. Adv Nutr 1:31-37. He, W.L., K. Furukawa, M. Toyomizu, T. Nochi, C.A. Bailey, and G. Wu. 2021. Interorgan metabolism, nutritional impacts, and safety of dietary L-glutamate and L-glutamine in poultry. Adv. Exp. Med. Biol. 1332:107-128. He, W.L., K. Furukawa, C.A. Bailey, and G. Wu. 2022. Oxidation of amino acids, glucose, and fatty acids as metabolic fuels in enterocytes of post-hatching developing chickens. J. Anim. Sci. 100:skac053, pp 1-14. Wu, G. 2018. Principles of Animal Nutrition. CRC Press, Boca Raton, Florida. pp. 1-772. Wu, G. 2022. Amino Acids: Biochemistry and Nutrition, 2nd edition. CRC Press, Boca Raton, Florida. pp. 1-787.