Five-star pig pens: China’s answer to superbugs
ON SHEN JIAN-PING’S antibiotic-free pig farm outside of Shanghai, biosecurity is something of an obsession. Vehicles entering the property are disinfected with a chlorine tire bath and alcohol spray, animals drink sterilized water and the closest visitors will get to seeing a live hog is via a TV in the visitors’ center.
The wiry 46- year- old has spent 4.7 million yuan ($700,000) giving his swine roomier, better-ventilated digs and there are three full- time veterinarians to help keep the 465- sow herd healthy. “It’s like the piglets are now living in a villa that’s clean and comfortable,” said Mr. Shen as he sipped green tea on the patio outside his office. “And it smells much better.”
Mr. Shen is in the vanguard of a new approach to livestock management in a country that consumes half the planet’s pork — and half its infection-fighting medicines. China’s over-reliance on antibiotics in food production places the country at heightened risk of spawning superbugs, genetically evolved bacterial strains resistant to current medicines that experts fear could trigger a global health crisis.
Antibiotics have been routinely fed to livestock to prevent disease and spur growth in dozens of industrialized countries for decades. However, in China pig feed typically contains multiple types of bacteria- killing drugs that are used in far greater volumes, said Ying Guang- Guo, professor of environmental chemistry and ecotoxicology with the Chinese Academy of Sciences in the southern city of Guangzhou.
Chinese pigs consume about 19,600 metric tons of antibiotics annually through their feed, scientists estimated in a 2013 study. The average growing pig in China excretes 175 milligrams of antibiotics per day in its urine and feces, according to Mr. Ying’s research. He extrapolated that across the nation’s entire pig population to estimate that 2,460 tons of drugs are released annually. Those chemicals may then leach into water wells and streams, or contaminate manure used to fertilize vegetable fields. Traces have even been found in Shanghai drinking water and school kids.
This epic outpouring of antibiotic residue in China is a golden opportunity for bacteria, and the genes that the microbes accumulate, to fine-tune their defenses and create new superbugs that can evade modern medicines. “It’s gene pollution,” said Zhu YongGuan, who runs the Institute of Urban Environment within the Chinese Academy of Sciences. “The danger is that these genes can be very mobile. They can be carried by bacteria and the bacteria can travel globally by air travelers, and through the movement of water or commodities.”
Hog farmer Mr. Shen knows his pig feed. Before starting his piggery five years ago, he made and supplied fodder to swine farms near his home town of Tongxiang, 130 kilometers ( 80 miles) from Shanghai.
He worries most about excessive use of colistin. Developed for humans in the 1950s, doctors quickly stopped using it because it damages the kidneys. That didn’t prevent its application in poultry and pig farms in Europe, China, Brazil and India.
Now, faced with patients with superbug infections, doctors consider the drug a treatment of last resort. Last November, scientists reported a colistin-resistant gene in China known as mcr-1, which can fortify a dozen or more types of bacteria and has been found in patients, food and environmental samples in at least 20 countries. Four patients have been infected with it in the US, the Centers for Disease Control and Prevention said this month.
About 11,942 tons of colistin, worth $187.2 million, was used worldwide in 2014, according to Beijing-based QYResearch Medical Research Center. Of the 10 largest producers of colistin, one is Indian, one is Danish and eight are Chinese, it said in a report last year.
Pig farmers are largely unaware of the drug’s importance or the need to restrict it, Mr. Shen said. “Most of them only wish to grow pigs faster,” he said.
That rankled with Mr. Shen, who traveled to Belgium and the Netherlands in 2011 to study how farmers there were raising hogs without antibiotics so he could try to replicate their methods back home.
His initial attempt failed. Sixty percent, or more than 1,000, of his swine died in the first winter. “We didn’t know how complicated it would be,” said Mr. Shen, who said he obtained a distance-learning degree in poultry production from China Agricultural University.
Marc Huon, a pig-management specialist in Belgium, was hired to redesign Mr. Shen’s pigsty. The first priority, Mr. Huon said, was to give each pig more space, better ventilation and to remove stress on the animals caused by temperature fluctuations. He also recommended a higher-protein diet based on a broader range of nutrients and the addition of supplements, including prebiotics to promote helpful intestinal bacteria in the pigs.
Water piped into the temperaturecontrolled barn has been filtered and purified with charcoal, and heated and irradiated to remove pathogens. “The water our pigs drink is better than the tap water in Shanghai — much better,” Mr. Shen said. These days, mortality is 5% to 6% — much less than the 15% to 16% average on neighboring piggeries, he said.
It takes Mr. Shen’s pigs about eight months to reach the 115 to 135 kilogram ( 250- 300 pound) target weight for slaughter. That’s four to five weeks longer than pigs fed antibiotics and other growth promoters, according to Mr. Huon. The Belgian’s nutrition plan emphasizes meat quality over weight gain. “It’s just a copy and paste of what we are doing here,’’ Mr. Huon said over the telephone from Belgium.
The Netherlands and Belgium have been reducing the use of antimicrobial drugs on farms for years, following Denmark’s lead in banning the nontherapeutic use of antibiotics in pigs in 1999.
The antibiotic- free status of Mr. Shen’s meat is validated by an independent auditor. Mr. Shen said he’s thought about going organic, but says it’s too difficult to source fully organic fodder. As it is, antibiotics are used only to treat sick pigs, with the meat from those animals sold separately to local butchers. A QR code on the pack of every antibiotic-free product Mr. Shen sells enables shoppers to view real- time images of his piggery using their smartphones.
“I explained to Shen four years ago that this would be a good solution for him to distinguish himself from the others,” Mr. Huon said. “Today, the biggest problem is that farmers only think about money.”
That said, there’s is a growing public awareness of food production safety, said Mr. Ying, the researcher in Guangzhou, who’s published more than 100 papers on antibiotic emissions and environmental contamination in China. “Ordinary people are very worried nowadays because of the media reports,” he said. “There is big pressure to do something.’’