Reuters reports that China has worked to restore herd numbers after the deadly fever first hit in 2018, but the threat lingers. A total of 10 African swine fever outbreaks have been reported this year in China.

Despite quickened recovery in hog production and improved market supply this year, costs of hog breeding are increasing and the efficiency of sow reproduction is lower than normal, the ministry said in an article which cited a meeting chaired by agriculture vice minister Ma Youxiang.

"The work to stabilise hog production shall not be relaxed," the article said, citing the meeting which was attended by representatives of 14 large-scale hog breeding companies.

Live hog futures on the Dalian Commodity Exchange closed down 4.8% at 23,550 yuan per tonne on Wednesday, partly driven by expectations of improving production.

The sow herd in April stood at 97.6% of the end-2017 level, data from the agriculture ministry showed.

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