The concept of biological feed was put forward in the last decade, and the comprehension of its definition and connotation is changing with the development of science and practice. Broadly, biological feed shall include all feed or raw materials except the synthetic additives.  Worldwide biological feed products have developed dozens of varieties to have become a major industry, mainly including the feed enzyme, forage amino acid and vitamin, probiotics (directly feeding microbes), forage oligosaccharides, natural plant extract, bioactive oligopeptides, feed biological pigment, new feed protein, biological medicine feed additive, etc. In China,we paid more attention to produce forage enzyme, probiotics, bioactive oligopeptides, oligosaccharides, etc. in the research and production process, which are inseparable from microbial culture medium.

A multitude of applications of chemical fertilizers and pesticides have both advantages and disadvantages for human beings. In order to eliminate the disadvantages, scientists have proposed ecological agriculture, which gradually realizes to use fewer or no chemical fertilizers and pesticides in farmland, and organic biological fertilizers and microbial methods to control diseases and insect pests. Existing biological fertilizers are based on organic matter culture medium and then mixed with inoculum and inorganic fertilizers. In order to improve this general and traditional situation extensively, biological fertilizers go far beyond existing concepts. It will provide both crop nutrients and soil improvement; meanwhile, the soil should be disinfected, that is, biological (mainly microorganisms) decomposition and elimination of pesticides (pesticides and fungicides), herbicides and pollutants from petrochemicals in the soil, as well as the remediation of soil.