关键词: 蛋氨酸, 来源, 鸭, 需要量, 相对生物学效价

Abstract: Methionine is the first limiting amino acid for poultry when fed with corn?soybean meal diet. It plays an important role in maintaining the normal growth and laying performance of poultry. However，the research progress of methionine is mainly focused on chickens and few studies are on ducks. So far，the DL ? methionine，methionine hydroxyl analogue and L?methionine are commonly used in poultry. But they are absorbed and transferred in different ways to form L?methionine，and the efficiency is different. Methionine and its hydroxy analogues are absorbed through the front end of digestive tract，duodenum or ileum，and L ? methionine is produced by rate ? limiting enzymes andtransaminases. They participate in a variety of metabolic pathways in liver and other tissues，promote protein synthesis，provide methyl donors for methionine cycle，and improve antioxidant properties. Therefore，this article summarized the function of methionine and its application in ducks，including the apparent digestibility of methionine in duck，the optimal requirement and bioefficiency between resources in meat ? and egg ? ducks，in order to provide scientific basis for the application of methionine in duck production.

Key words: Methionine, Source, Duck, Requirement, Efficacy