The immunological function of cattle and poultry muscles is tightly linked to tryptophan. For example, when pigs develop chronic pneumonia, their plasma tryptophan level drops gradually; adding 0.04 percent tryptophan to the diet can significantly increase the spleen index of ducklings, and adding 0.06 percent tryptophan can significantly increase their thymus index; adding tryptophan to the diet of chickens can significantly increase the level of interferon and immunoglobulin G (IgG), and significantly enhance the body's immune protection against pathogens; adding tryp The addition of 0.05 percent tryptophan to the diet significantly increased the weight of immune organs such as the thymus, bursa, and spleen of laying ducks; the addition of tryptophan to the diet significantly increased the spleen index of Yangzhou geese and improved immune protection against infectious bursal disease; the addition of tryptophan to the diet significantly increased the weight of immune organs such as the thymus, bursa, and s By boosting IgG and immunoglobulin M production, tryptophan supplementation enhanced the spleen index of Yangzhou geese and improved their humoral immunity.
According to the above, when an inflammatory response occurs, the need for tryptophan in the muscle increases, and tryptophan catabolism is increased; adding a certain dose of tryptophan to the diet aids the development of the immune organs of livestock and poultry, as well as improving muscle immunity. 5-HT, N-acetyl serotonin, and melatonin are all produced when tryptophan is broken down. By scavenging free radicals and blocking the nuclear transcription factor kappa B from accessing the nucleus, the 5-HT, N-acetyl serotonin, and melatonin generated by tryptophan metabolism can limit the generation of tumour necrosis factor-, so improving the body's immunological function.
Furthermore, via modulating nitric oxide synthase, N-acetyl serotonin can impact the creation of inducible NO, hence influencing the body's immunological function. T lymphocyte differentiation and metabolites play an essential role in the maturation of B lymphocytes, which influences the capacity of B lymphocytes to release IgG, and tryptophan catabolism can accelerate the differentiation of bone marrow T lymphocyte precursors into mature T lymphocytes.
According to several recent studies, tryptophan is linked to the antioxidant activity of the muscle. The addition of 0.18 percent tryptophan to the feed of yellow-finned broiler breeders can improve blood superoxide dismutase (SOD) activity and glutathione (GSH) content, as well as considerably boost serum glutathione peroxidase activity. Melatonin is linked to tryptophan's antioxidant action. Melatonin is a multifunctional hormone that has been shown to have antioxidant properties in several investigations. Melatonin is an electron-rich aromatic indole ring that scavenges numerous free radicals and works as an antioxidant when it combines with electron-philic free radicals.
Melatonin is also oxidized at all levels to produce cyclic 3-hydroxy melatonin sulphate, 6-hydroxy melatonin sulphate, and N-acetyl-N-formyl-5-methoxyuramine metabolites, all of which are antioxidants. These metabolites prevent peroxidation in the muscle by supplying free electrons to scavenge reactive oxygen species or by increasing SOD and GSH-Px activity.