"It simply takes time to increase the number of piglets and to rear pigs,"the vice chairman of China Animal Agriculture Association, Qiao Yufeng, said.

A breeding cycle usually takes one year, making it difficult to increase market supply quickly.

"And this (shortage) happens at a time when prices of agricultural products, which are used to produce the feed, are rising quickly," Qiao said on the sidelines of an industry conference in Shanghai Friday.

Prices of soybean, soymeal and corn, which are used to make animal feeds, have all been growing fast, and unfavorable weather conditions have made industry participants believe that prices are unlikely to see a sharp fall any time soon.

"Besides the cost of feed demand, higher expenses in disease prevention, and the shortage of rural labor all underpin the prices," Qiao said.