Abstract: A reasonable nutritional regulation plans contribute to decreasing the intestinal stress response of farmed animals, reducing the use of antibiotics and other drugs, and building a new system of efficient green farming technology. Unlike traditional neutral feed oligosaccharides such as fructooligosaccharides and xylooligosaccharides, alginate oligosaccharides （AOS） are a natural active substance prepared from marine algae, which are binary linear block compounds composed of β-D-mannuronic acid （M） and α-L-guluronic acid （G）. AOS contain multiple active carboxyl groups in addition to active aldehyde and hydroxyl groups, with unique chemical structure and biological activity, which are now applied in many fields such as medicine, food, animal husbandry, etc., attracting much attention from scholars. Based on the latest research progress at home and abroad, this study reviewed the sources, preparation methods, characterization methods, biological activities, and application of AOS in pig industry, with a view to providing theoretical support for the scientific use and promotion of AOS in healthy animal breeding.

Key words: alginate oligosaccharides, feed additive, pig breeding