\u00a0China found its second case of African swine fever (ASF) on Thursday at a slaughterhouse owned by WH Group Ltd\u2019s Chinese unit, stirring concerns about the spread of the deadly infection across the world\u2019s largest pig herd.\r\nSome 30 hogs died of the disease at the slaughterhouse in Zhengzhou in central Henan province, the Ministry of Agriculture and Rural Affairs said in a statement. The pigs had traveled thousands of kilometers from a farm in Jiamusi city in China\u2019s northeastern province of Heilongjiang, it said.\r\nLocal authorities suspended operations and sealed off the slaughterhouse, controlled by China\u2019s largest pork processor Henan Shuanghui Investment & Development, a subsidiary of WH Group, a WH spokeswoman confirmed with Reuters.\r\nThe outbreak comes almost two weeks after another northeastern province, Liaoning, culled thousands of pigs after the discovery of China\u2019s first case of African swine fever.\r\nThe agriculture ministry did not name the company in Zhengzhou, but Shuanghui Investment & Development reported earlier on Thursday that it had discovered a suspected case of the disease, a director of the Heilongjiang Provincial Animal Husbandry and Veterinary Bureau told Reuters.\r\nHeilongjiang authorities were investigating whether the pigs were infected in the northeastern province bordering Russia. The provincial veterinary official said it wasn\u2019t clear where or how the pigs in Zhengzhou caught the disease.\r\n\u201cWe have sent two batches of experts from the (Heilongjiang) province and central government to Tangyuan this morning, where the suspected outbreak was reported,\u201d the official said.\r\n\u00a0\r\nTangyuan is a county in Jiamusi city.\r\nShuanghui has diverted orders from its Zhengzhou operations and is cooperating with the authorities to contain the disease, a staff member in the media relations department of Shuanghui said.\r\nNeighboring factories will supplement supplies and sales from the slaughterhouse during its suspension. Shuanghui\u2019s production capacity and production in the region will not be affected, the WH spokeswoman said.\r\nThe pigs in question did not enter the slaughtering process because the problem, later identified as ASF, was discovered before that, the spokeswoman said.\r\nAfter the first outbreak in Liaoning, which was also the first in East Asia, Japan suspended imports of heat-treated Chinese pork and has tightened quarantine operations at airports and seaports.\r\nVAST DISTANCE\r\nThe vast distance the pigs in Henan traveled - some 2,300 km (1,440 miles) southwest from Heilongjiang to central China - highlights the challenge for the government in controlling the highly contagious disease in the country\u2019s vast hog population and beyond its borders.\r\nHenan is China\u2019s second-largest pig producer, and is a big supplier to nearby Shandong, Sichuan and Hubei provinces.\r\n\u00a0\r\n\u201cThe issue is quite serious now that the disease just hit the center of pig production,\u201d said Yao Guiling, an analyst at consultancy China-America Commodity Data Analytics.\r\n\u201cThe outbreak might be more severe than just the two cases that have been confirmed.\u201d\r\nShares in Shuanghui sank 10 percent on Thursday amid concerns about the impact of the disease on sales. Other large hog farmers, Muyuan Foods Co and Guangdong Wens Foodstuff Group Co, were also sharply lower.\r\nThe disease is the latest blow to Chinese hog farmers, who have been struggling with a prolonged rout as years of frenzied investment to boost production have created oversupply, with output well beyond stagnating domestic demand.\r\nASF is one of the most devastating diseases to affect swine herds. It occurs among pigs and wild boars, transmitted by ticks and direct contact between animals, and its effects are often deadly. There is no vaccine.\r\nThe disease does not affect humans.\r\nShuanghui, headquartered in Luohe, Henan province, has 15 slaughterhouses, with a total annual capacity of 30 million hogs, and 23 production bases across China, spanning from Heilongjiang to the southern province of Guangdong.\r\nShuanghui sells more than 3 million tonnes of pork a year.