• Case at Zhengzhou slaughterhouse is second in China
• Stirs concerns about spread across world's largest pig herd
• WH Group shares up 1.2 pct of Fri after 10 pct slump on Thu

BEIJING: WH Group Ltd, the world's top pork producer, on Friday said it had been ordered to shut a slaughterhouse in central China for six weeks after pigs there died of African swine fever (ASF) in the country's second case of the disease.

Some 30 hogs died of the illness on Thursday at the slaughterhouse in Zhengzhou in Henan province, controlled by China's largest pork processor Henan Shuanghui Investment & Development, a subsidiary of WH Group.

Shuanghui said in a separate statement on Friday it culled 1,362 pigs at the plant after the infection was discovered.

The infected pigs had travelled thousands of kilometres from a farm in Jiamusi city in China's northeastern province of Heilongjiang, stoking concerns about the spread of the highly contagious disease across the world's largest pig herd and into East Asia.

WH Group said in a statement that the temporary closure was ordered by Zhengzhou city authorities. Henan is China's second-largest pig producer.

The company, whose shares sank 10 percent on Thursday, said it did not expect the closure to have any adverse material impact on its business.

The Zhengzhou operation accounts for an "insignificant" portion of WH Group's operations and it does not expect any disruption to supply of pork and related products as a result of the temporary closure, it said. On Thursday, Shuanghui said it had diverted sales orders to other operations.

WH Group shares were up 1.15 percent and Shuanghui were up 2.6 percent in early trading on Friday.

Meanwhile, Heilongjiang authorities have been investigating whether the pigs were infected in the northeastern province bordering Russia. It was unclear where or how the pigs in Zhengzhou caught the disease.

The outbreak comes almost two weeks after another northeastern province, Liaoning, culled thousands of pigs after the discovery of China's first case of the fever.

ASF 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. Its effects are often deadly, and there is no vaccine. It does not affect humans.