Methionine (Met) is found in humans and animalsEssential sulfur-containing amino acidsIt cannot be synthesized by itself and must be ingested through food or feed. It is first used in the bodyProtein synthesisIt is also the starting residue for translation, and at the same timeS-adenosylmethionine (SAM)It is a precursor, thereby driving a wide range ofMethylation reaction(nucleic acid/protein/lipid methylation, neurotransmitter and phospholipid metabolism, etc.), and through steeringCysteine → glutathione (GSH)Path participationDetoxification and antioxidationMaintain liver function and cellular restorative homeostasis; It is precisely because it is most likely to be "insufficient" in many plant-based diets (especially as the first limiting amino acid for poultry) that it is often used as a key nutritional fortification and feed additive component to enhance growth, meat/egg production efficiency and nitrogen utilization.