In poultry feeding, methionine hydroxy analogues show properties similar to those of amino acids known to act as growth stimulants, making them important additives to animal feed. Methionine is an important and essential amino acid for animals. Methionine hydroxy analogues can be converted to methionine in the animal's body and fulfil its nutritional role. Methionine hydroxy analogues can effectively act as acidifying agents in diets, buffer the neutralisation of gastric acid by high alkaline ingredients in diets, enhance the acidic environment of the gastrointestinal tract, increase the activity of pepsin and duodenal trypsin, thus promoting the digestion and absorption of nutrients, especially proteins, and facilitating growth. In addition, it can also be used as a rumen protein source for ruminants and acidifier for piglet diets, which can reduce heat stress, can reduce nitrogen excretion replication of the full text of the leakage, to protect the environment, and improve the body's immunity. Methionine hydroxy analogues are bacteriostatic and can prevent diarrhoea.