Abstract:As a new type of roughage with wide material source, low production cost and easy storage, yeast feed is widely used in livestock and poultry production. The study found that fermented feed has the advantages of green environmental protection, improving rumen fermentation environment, promoting body growth and reducing feeding costs, and can also improve the growth performance of sheep, improve digestive system health, improve meat and milk quality, improve immune and antioxidant functions, and reduce rumen methane emissions. Therefore, this paper reviewed the principle, production process and application research of fermented feed in sheep breeding and production, in order to provide reference for further application of fermented feed in sheep.