Oxidative stress is associated with retarded growth and the initiation and progression of diseases in pigs. The carboxymethylation of chito-oligosaccharide (COS) can improve its antioxidant activity for such issues. Herein. an orthogonal experiment L9 (34) test design was used to optimise the preparation conditions of carboxymethyl (CM)-COS. https://unitedssports.shop/product-category/fan-shop-ncaa-hats/