China, which is also the world's biggest pork consumer, produced 42.55 million tonnes of the meat last year, down 21.3 percent from 2018, and the lowest output since 2003, according to National Bureau of Statistics (NBS) data.

African swine fever (ASF) reached China in 2018 and spread to farms across the country.

China's food prices have soared as pork costs have increased amid the supply shortage, driving inflation close to an eight-year high in the world's second-largest economy.

The Ministry of Agriculture and Rural Affairs reported China's hog herd had declined in October by 41 percent from a year earlier but rose by 2 percent in November. That data did not give a total herd size.

On Friday, the NBS said the pig herd declined 27.5 percent from a year earlier to 310.41 million head by the end of December. That is up from the 306.75 million head it reported for the first nine months of the year.

Some analysts and industry insiders have disputed the official government toll on the herd size, believing the decline was larger.

The NBS also reported that the number of slaughtered hogs last year fell 21.6 percent to 544.19 million head.

Rabobank forecast in November that China's pork production would shrink by 25 percent in 2019 to about 40.5 million tonnes, and a further 10 percent to 15 percent in 2020.

The government has sought to stabilise prices by releasing hundreds of thousands of tonnes of frozen pork from reserves. Imports have also surged, with December arrivals of pork meat almost double the previous monthly record.

Total meat output including pork, beef, lamb and poultry fell 10.2 percent in 2019 to 76.49 million tonnes, the NBS data also showed.