And those pigs were about to be carted off for slaughter. Ee-i-ee-i-oh.
That is the message of "Ten-Minute Exit", a Bedford-based exhibition using primary-school choruses of the children's rhyme to make a connection between the pigs which build stick houses or run home screaming "wee wee wee" and those which form the filling in a bacon sandwich.
Patricia MacKinnon-Day, the artist who developed "Ten-Minute Exit", says it gives an account of conditions in pig farming and makes the connection between Porky the Pig and pork chops. "I'm telling how pig farming is, the basic truth of what happens," she said.
Ms MacKinnon-Day has compiled video footage of cartoon pigs dancing to children's choruses of Old MacDonald, and intersperses them with images of people eating bacon. She has also assembled toy models of pigs in pens portraying how they behave, following sessions observing what went on at a pig farm.
Ms MacKinnon-Day said she is not an advocate of animal rights or vegetarianism, but is interpreting academic research conducted by Elizabeth Genever, who studies animal behaviour at Cambridge university.
Ms Genever said: "A lot of people think about animals, especially pigs, in a cartoon way. They don't really move on from the idea that they are cute and funny. But there are thousands of pigs living in concrete pens, in conditions that aren't what they should be."
Michael Seals, of the National Farmers' Union, said: "People like their bacon butties, but sadly they come from a pig. It's one of those facts of life. But standards of pig-farming are very high."
Christine Page, head of Bourn primary, in Cambridge, whose pupils sang the choruses of Old MacDonald used in the exhibition, said: "Showing the reality behind Old MacDonald is a bit like telling children that Father Christmas isn't real."
Ten-Minute Exit is at the BCA gallery, in Bedford, until December 18.www.bedfordcreativearts.org