1. The investment required to build a fermentation bed varies from person to person, depending on the scale and local prices and wages. The cost of making fermentation bed by strains from different manufacturers is also different. The total cost of making fermentation bed should be calculated, including: unit price of strains, dosage per square meter, number of viable bacteria per gram, survival time and replenishment period of strains, padding cost, auxiliary material cost, nutrient solution cost, complexity and cost of daily maintenance, labor cost and failure risk cost. Some strains may not cost money, but the production time and cost of "tofu wants meat" are much higher than that of purchasing professional strains; The unit price of other strains is very cheap, but the operation of various nutrient solutions, amino acids, additives, too many thick padding and auxiliary materials is cumbersome, and the total cost has overwhelmed users. Under the condition of the same quality, the lower the total cost, the simpler the operation and the more advantageous the fermentation bed products are.
2. The fermentation bed is an environmentally-friendly, safe and effective way to raise pigs, which adopts a brand-new concept of natural agriculture and combines modern microbial fermentation treatment technology. It realizes zero emission, no pollution and no peculiar smell, and completely solves the environmental pollution problem of large-scale pig farms. It is a virtuous circle ecological pig raising system that integrates pig raising science, nutrition, environmental hygiene, biology and soil fertilizer science and follows the principles of low cost, high output and no pollution. It is another highlight of the development of industrialized large-scale pig raising to a certain stage, and it is a new model for the sustainable development of pig raising industry.