Under the pressure of environmental protection, various environmental protection models have emerged, most of which are from the perspective of manure treatment. For example, Guangxi proposed to improve the digestibility of feed through microbial fermentation of feed, thereby reducing the discharge of manure and urine. However, the practice of adding microorganisms to feed has already existed. Why did it arise at this time? Is it useful for environmental protection? What are the experiments and practices? Under the pressure of environmental protection, various environmental protection models have emerged, most of which are based on the perspective of manure treatment. However, in some places, control of manure production from the source has emerged to reduce the pressure of sewage discharge. For example, Guangxi proposed to use the mouth Pollution control, with microorganisms as the core, improve the digestibility of feed through microbial fermentation of feed, thereby reducing the discharge of feces and urine. However, the practice of adding microorganisms to feed has already existed. Why did it arise at this time? Is it useful for environmental protection? What are the experiments and practices? 　　Improve digestibility and reduce sewage discharge The rise of 　　 microorganisms is related to the recently advocated ecological farming model. To understand the application of microorganisms in pig raising, the best case is the Guangxi model. According to official information, the Guangxi model applies microbial technology to the entire breeding process. One is to ferment feed with microorganisms (probiotics) to establish a benign microbial flora in the animal intestine, improve feed utilization, and promote healthy animal growth. Improve animal immunity, reduce morbidity, reduce the amount of veterinary drugs, improve product quality and improve product quality and safety; second, use microorganisms to control the environment, eliminate and inhibit the breeding of harmful bacteria in the breeding environment, and reduce the risk of animal diseases; third, use microbial fermentation Livestock and poultry manure, the organic matter that degrades manure, effectively inhibits manure rancidity and the breeding of flies and mosquitoes, which is conducive to the production of harmless and efficient biological organic fertilizer. 　　 In an article introducing the transformation of Guangxi's animal husbandry in February 2017, it was mentioned that the use of microorganisms can produce the effect of "four or two funds". Adding probiotics such as Bacillus subtilis and Enterococcus faecalis in the feed can adjust the acidity and alkalinity of the feed, improve the intestinal environment, promote feed absorption, reduce fecal odor, and can also improve the immunity of pigs and greatly reduce the amount of antibiotics. . 　　As a representative pig farm of Guangxi model, Chen Zhonghong, general manager of Qichang Breeding Pig, introduced that according to his test, the use of microorganisms can reduce fecal volume by 17%-18.5% and urine output by 25%-27%. Improving intestinal health and improving digestibility are the analysis of the effects of emission reduction by many industry professionals. 　　Chen Zhonghong introduced that the microorganisms added to the feed mainly include bifidobacteria, bacillus and yeast, etc., and the flora required by piglets, piglets and sows is different. By improving intestinal health, increasing feed digestibility, thereby reducing stool volume. And once fermentation has been carried out in the intestinal tract, it also has certain benefits for subsequent organic fermentation. 　　 The reporter has also noticed on many occasions that the effect of reducing emissions has become a standard for propaganda of many microbial fermented feeds. 　　 has the effect of reducing emissions, but only incidental 　　 However, most pig farms are only sensory in reducing emissions. For example, a farmer in Wuzhou, Guangxi, Kong Fanwei, said that he has obvious feelings about reducing odor, but he has not done data on reducing emissions. Many people in the industry also said that the effect is definitely there, but it is hard to say how effective it is. 　　 Many people in the industry said that "it may have a certain effect, but it is only a side effect." Chen Zhonghong also said that, in fact, his initial experiment with microbes in his pig farm was not to reduce pollution, but to reduce the cost of breeding, so that pig manure could be requested. Later, after the environmental protection policy came down, he just discovered that this model was in line with national environmental protection requirements. So it is promoted vigorously by the government. 　　 Actually, microorganisms have been used for many years, but why has it suddenly become popular? According to Professor Huang Weijian of Guangxi University, this is related to the improvement of pig farm facilities and the change of breeding environment. Kong Fanchuan, a farmer in Wuzhou, Guangxi, said that his pig farms had tried to use probiotics many years ago, but they did not use them again if the results were not seen, and the quality of probiotics has indeed been greatly improved in recent years. 　　 However, the choice of microorganisms is still a troublesome thing. "So far, there is no benchmark product that can win the reputation of the industry." said Chen Wuyi, general manager of Guangdong Merico's veterinary drug chain service system. Many people in the industry told reporters that the ecological model with microbes at its core is in a stage of exploration, and it will take time to prove its role.