Swill, also known as swill, as a kind of wastewater in our life, whether in rural areas or cities, especially with the vigorous development of catering industry, swill in hotels is increasing day by day. Hotels, restaurants and schools are continuously exported, but as long as they are fully utilized, they can also have rich returns. Leftovers collected from hotels, restaurants, schools and so on. It has low cost and rich nutrition, and is a good feed for raising pigs.

The biggest disadvantages of taking swill privately are: firstly, the collected swill needs high-temperature disinfection and sterilization, and besides spending a lot of fuel costs, the staff is also very hard; Secondly, the nutrition is also unbalanced, especially the protein of plants is scarce, and the protein of animals is relatively surplus and the quality is not good, so it takes six or seven months to go public. Thirdly, the components in decanted water are complex, and there are many toxic and harmful substances, which are easy to cause the threat of various infectious diseases and parasitic diseases. Sick pigs and dead pigs occur from time to time, and the risk of loss is great; Finally, it is easy to deteriorate and the preservation time is not long. It is reported that swill fermented into feed has achieved good results in pig industry.

Swill can be fermented into safe feed by microorganisms, and the fermented liquid of Nongshengle feed has made some achievements in this respect. It can not only shorten the slaughter time (from the past six to seven months to less than five months), but also greatly save fuel and labor costs, reduce labor intensity, and achieve or exceed the effect of full-price feed. The raised pigs have rosy skin and bright oil, and the whole pigsty has no peculiar smell and the environment is fresh.