"The farm owns 2,500 hectares of land, which is where we dump all the waste.
"We don't usually call it waste - it is fertilizer. It helps the crops grow which then feed the pigs."
Villagers sometimes complain about the smell. Smithfield officials say this is because they are resentful because they wanted to be employed on the farm.
"During the communist era a farm like this would have employed 100 people - but profit wasn't so important then," an official added.