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

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

　　Feed additives can be divided into microbial feed additives and Chinese herbal feed additives. Among them, microbial feed additives are microbial products that replace or balance one or more strains of bacteria in animal ecosystems. In a narrow sense, it is a kind of microbial product that can stimulate the growth of beneficial bacteria and resist the growth of harmful bacteria. Microbial feed additives contain a large number of beneficial bacteria (active lactic acid bacteria, bifidobacteria, Bacillus), complex enzymes, chelating peptides, demilding agents and so on. As feed into livestock and poultry, microbial feed additives can rapidly multiply. On the one hand, the metabolites of bacteria and enteric endotoxins inhibit the growth of other harmful bacterial flora, on the other hand. On the other hand, it forms normal microbial flora in the host, synthesizes the main vitamins for the host, provides nutrition and prevents the invasion of pathogenic bacteria.