Microbial feed additive

The invention relates to a microbial feed additive and belongs to the field of an agricultural microbial feed additive. The microbial feed additive is prepared by compounding three microbes, namely bacillus subtilis, clostridium butyricum and saccharomyces cerevisiae according to a certain ratio, wherein bacillus subtilis and clostridium butyricum adopt liquid fermentation and saccharomyces cerevisiae adopts liquid-solid fermentation. As for solid culture, solid fermentation of a culture medium prepared by using lucid ganoderma cultural residue, wheat bran and the like as raw materials is carried out. The microbial feed additive is used for livestock breeding, can effectively raise immunologic functions such as disease resistance, disease prevention and the like of piglets and chicks and reduce death rate, and can be used in laying hens to enhance egg yield and improve egg quality. The microbial feed additive is of great significance for promoting sustainable development of poultry breeding industry and guaranteeing product quality and safety.