Feed additives refer to small or trace substances added in the process of feed production, processing and use. They are used in small amounts but have significant effects. Feed additives are inevitable raw materials used in the modern feed industry. They have obvious effects on strengthening the nutritional value of basic feeds, improving animal production performance, ensuring animal health, saving feed costs, and improving the quality of animal products.

Feed additives are divided into microbial feed additives and Chinese herbal medicine feed additives. Among them, the microbial feed additive is a microbial product that replaces or balances one or more bacterial strains in the animal ecosystem.
In a narrow sense, it is a microbial product that can stimulate the reproduction and growth of its own beneficial bacteria while resisting the growth of harmful bacteria. Microbial feed additives contain a large number of beneficial bacteria (active lactic acid bacteria, bifidobacteria, bacillus), compound enzymes, chelated peptides, mold removers, etc. After entering livestock and poultry as feed, they can multiply rapidly. The metabolites neutralize enterotoxin and inhibit the growth of other harmful flora. On the other hand, it forms a normal microbial flora in the host, synthesizes the main vitamins for the host, provides nutrients and prevents the invasion of pathogenic bacteria.