Abstract: Astragalus membranaceus is a perennial herb belonging to the genus Astragalus of the Fabaceae family. It is mainly produced in Inner Mongolia, Gansu, Xinjiang, Shanxi, Shaanxi, Heilongjiang and other regions in China. A. membranaceus has functions such as consolidating the exterior to arrest sweating, tonifying qi and raising yang, as well as promoting diuresis to alleviate edema. As a natural plant with dual medicinal and edible values, it is widely applied in clinical traditional Chinese medicine and health care. In recent years, it has attracted extensive attention from the farming industry due to the multiple functions of its active ingredients in animal health care and nutritional regulation. A. membranaceus is rich in bioactive substances including polysaccharides, flavonoids and triterpenoid saponins, and exhibits various physiological functions such as anti inflammation, antioxidant, anti stress and immunomodulation. By systematically discusses the research progress on the application of A. membranaceus in ruminant production, this paper reviews relevant studies on its abundant active substances and biological functions, as well as recent research regarding growth performance and feed efficiency, immunoregulation and disease resistant effects, antioxidant and anti stress capacity, gastrointestinal microenvironment regulation and livestock product quality improvement in ruminants. Combining the industrial background of antibiotic restriction, antibiotic substitution and healthy farming in the current farming industry, this paper further analyzes the application prospects and limiting factors of A.membranaceus as a natural plant additive, aiming to provide references for the research and application of A.membranaceus in ruminant farming.

Key words: Astragalus membranaceus, ruminants, active substances, growth performance, immunoregulation