Research progress on biological functions of astragalus stems and leaves and their application in cattle production: a review

<i>Astragalus</i> stems and leaves (ASL) represent a promising feed additive to improve cattle health and production efficiency. They are rich in nutrients and active substances, such as polysaccharides, flavonoids, alkaloids, exhibit antioxidant, antibacterial, anti-inflammatory, and other biological functions. With the advantages of high yield and low price, ASL are excellent potential feedstuff resources that could alleviate the shortage of conventional feed and reduce feeding costs. This review highlights the botanical characteristics, phytochemical components, nutritional and pharmacological effects of ASL, as well as their applications in cattle production, which could be beneficial for animal nutrition regulation and forage development.