A complicated enzyme system and microorganisms are used for acting on straws and food industrial residues to convert the straws and the food industrial residues into glucose and part of oligosaccharide, amino acids, small peptides, inositol and nucleic acids and to supply mineral substances, trace elements and nutritional substances such as vitamins in the straws and the food industrial residues to monogastric animals for use. Through adding of Chinese herbal medicines, the digestion function of a monogastric animal may be enhanced, and the immune function of the monogastric animal may be enhanced, thereby reducing occurrence of diseases. In addition, the complicated enzyme system supplements exogenous enzymes in a digestive tract of the monogastric animal to reduce protein and phytic acid residues in excrements, reduce odor and improve the environment of a hog house, thereby obviously reducing drug and treatment costs.