When discussing the pig carcasses floating in the river in Shanghai, Yang Shengguan, a farmer from Zhulin village in Zhejiang province became emotional.

"They said these pigs were from our village; they obviously don't know the real conditions here," said Yang, who with his wife raises 100 pigs in a concrete building next to their house.

"In our village, almost every family raises pigs, some even raise more than 1,000," he said, adding that the price of pork has declined in recent years and the discovery of the carcasses will put even more pressure on hard-pressed villagers.