Restaurant Garbage Replaced by Corn and Soybean Meal?

Did the Chinese government's ban on swill-feeding of pigs to prevent spread of African swine fever (ASF) in 2018 really stamp out the practice? Even if it didn't, the idling of food service establishments during 2020 surely cratered the supply of swill. Are grain-feeding swine farms now replacing swill-feeders?

The long history of feeding food scraps and other waste to pigs in China shifted into high gear as the country's food service industry boomed over the past two decades. Restaurants, cafeterias, and hotels collected table waste in drums and bags, then sold it to dealers who picked it up in small vans and delivered it to surreptitious farms hidden in villages on the outskirts of cities. There, the garbage is cooked in vats and fed to dozens or hundreds of pigs held in rudimentary pens and sheds.

Restaurant waste is delivered in barrels to be cooked down and fed to pigs.
These were photographed at a farm on the outskirts of Kunming, China, in 2014.

Over the past decade, Chinese authorities have been trying to shut down swill-feeding farms to prevent spread of disease, poor sanitation, and to eliminate pollution from these farms. China's Livestock Law prohibits feeding garbage unless it has been treated properly at high temperature. In 2010, China's State Council ordered city mayors to strengthen oversight of food waste. The government was prodded by embarrassing publicity about so-called "gutter oil"--a by-product of cooking garbage to feed to pigs. Localities issued regulations banning the practice and imposing penalties. In 2011, the government started setting municipal systems to collect food waste and use it to generate electricity or dispose of it properly, and $100 million was allocated to subsidize demonstration projects. 

A widely-published "investigation" by a Xinhua reporter in 2017 described seeing several garbage-feeding farms in Tianjin being demolished by authorities. Yet he managed to find another one still in operation which he described in detail. As recently as April 2018, a local news site in Beijing reported finding a farm in the Tongzhou suburb that raised thousands of pigs on waste trucked in daily from the city.

When African swine fever hit China in 2018, the government ordered that swill-feeding farms be shut down after the Ministry of Agriculture and Rural Affairs found that ASF was spread by feeding food waste to pigs. 

This propaganda comic says the barrel of restaurant garbage is uncontrolled;
the "swill pig" spreads disease and pollutes the environment.

In February 2019, Chinese news media circulated a report of two farmers in Sichuan's Jintang County who were arrested for raising 600 pigs on food waste after it had been banned the previous October. This was widely posted, presumably as a warning to farmers. Another warning posted on social media in August 2019 explained the dangers of garbage-feeding, its role in spreading African swine fever, the government's crackdown, and penalties for engaging in the activity. A February 2021 article explained that farmers could feed waste to pigs that they consume themselves, but feeding restaurant garbage to pigs is banned and local governments offer a reward for turning in violators. 

Legitimate restaurant garbage collection and treatment programs are still in the pilot stage. The locality of Jiaxing in Zhejiang Province just announced a pilot program to produce electricity from biogas generated from restaurant waste. This locality has been a hotspot for model pig farms since it launched 10,000 dead pig carcasses into Shanghai's river 8 years ago.

A November 2018 article, "The State's Ban on Swill-Feeding Pigs to Ensure Swine Safety is Correct, but How Will So Much Waste be Treated?" wondered how China's huge volume of food waste could possibly be treated if swill-feeding farms were shut down. The article cited an estimate that the country produced nearly 100 million metric tons of restaurant waste in 2017 and another estimate that only 10 percent of restaurant waste was properly disposed of and treated. The author said there were many barriers to disposing of restaurant waste in a safe and sanitary way (including "illegal interests"--presumably profits enjoyed by criminal networks from selling "gutter oil" and pigs). 

The flip side of the article's concern is: If swill-feeding farms were shut down, would conventional grain-feeding farms replace the lost supply of swill pork? 

Swill-feeding could account for a significant proportion of China's pork output. If China's food service industry generated nearly 100 million metric tons of waste in 2017, let's guess conservatively that 20-to-50 mmt of that waste is fed to pigs (the rest is oil extracted for "gutter oil," inedible plastic, napkins, styrofoam, chopsticks, and stuff that rots or is actually disposed of). 

In comparison, China's feed industry association says 98 mmt of commercial swine feed was produced in 2017--which presumably does not include swill. That's about equal to the estimated volume of restaurant waste and could mean that a substantial portion of China's pork was fed swill pre-ASF. If swill-feeding farms are now replaced with conventional farms, that could translate to a 20-to-50 mmt shift from swill to commercial swine feed, requiring about 12-to-30 mmt of corn and 4-10 mmt of soybean meal as ingredients.

It's not clear whether swill farms were entirely closed down by regulators. People who flout rules and may be connected with criminal organizations are probably not easily scared off by fines and newspaper articles. But the closure of food service businesses during 2020 surely shrank the supply of swill when school and workplace cafeterias, hotels and restaurants were largely shut. China's food service business has been slow to rebound from Covid lockdowns. Moreover, the scarcity and high price of piglets surely cut back on the profitability of swill-feeding as well.

If the swill-feeders accounted for a lot of pork production, that could explain why so little commercial hog feed was produced pre-ASF. If they have been shut down now, it could explain why the demand for corn and soybeans is so vigorous if grain-feeding farms are replacing swill-feeders. This also raises the possibility of a resurgence in swill-feeding as the food service sector recovers, which might accelerate  the decline in hog prices to their break-even level.