Per capita consumption in the country was down to 24.8 kilograms in the period as supply fell by 200,000 tons, according to a report by market research firm Ipsos.

Yet Vietnam remained among the biggest pork markets in the world, it said.

Pork prices hit a 20-year high in March this year as the African swine fever, which is fatal to pigs but does not affect humans, broke out in February last year and caused pig numbers to fall by more than 25 percent.

The government has been increasing imports to keep prices in check. Imports surged 300 percent year-on-year in the first four months to 46,400 tonnes, or nearly 70 percent of total imports last year, according to the Ministry of Agriculture and Rural Development.

Pork is a main ingredient in the Vietnamese diet. Last year per capita consumption was five times that of beef, according to Ipsos.