The Chinese mainland saw a big-margin decline in pork export in the first four months of this year, due largely to mounting pig raising cost, sources with the General Administration of Customs said on Saturday.

From January and April, the Chinese mainland sold 24,000 tons of pork abroad, a decrease of 54.4 percent from the same period of last year.

The export value was $79.79 million, down 14.1 percent.

But the average price rose 96.4 percent year-on-year to $3,396 per ton.

Of the total exports, Hong Kong Special Administrative Region made up for 79.2 percent, or 19,000 tons, down 37.3 percent.

The sources believed the May 12 earthquake, which jolted southwestern province of Sichuan and claimed more than 69,000 lives, would help drive the pork export further down.

Prior to the 8.0-magnitude quake, Sichuan accounted for 11 percent of China's total pork output and nearly one third of the exports nationwide.