"I think every farmer's daughter dreams of being a butter head one day," said Miron, who's from Hugo, Minn.
The fair has had butter sculptures since the late 1800s but it wasn't until 1965 that the tradition of carving the heads of the dairy princesses began. They remain one of the fair's most popular attractions, spokeswoman Brienna Schuette said.
Princess Kay and her court each spend one day sitting in a revolving cooler while Linda Christensen, an artist who now lives in Oceanside, Calif., carves their likenesses in 90 pounds of butter.
"It's like opening your refrigerator, climbing inside and staying there," Miron said.
The princesses take their sculptures home after the fair. Some keep them in coolers for years, taking them out only for their wedding, where guests are invited to spread the artwork on bread or eat it in some other fashion. Others have used the butter to bake cookies for charity, or as Miron plans to do later this month, melt it on corn at a hometown corn feed.
Butter sculptures date back to ancient Tibet, where monks carved animals and deities out of yak butter, said Sherry Newell, a spokeswoman for the Midwest Dairy Association.
The tradition spread to North America in the early 1800s, and today there's a Facebook application where people can create photos of themselves carved in butter and have it printed on a postcard from one of nine Midwestern states, she said.
Welling said butter sculptures really took off in the early 1900s, when the dairy industry began using them as marketing tools.
"They really could rival great sculptures of art in their detail and as elaborate as they've become," he said.
Ohio's tradition started with a butter carving competition in 1903, and its cow eventually became a permanent display. The cow is accompanied by a companion piece, which over the year has included Darth Vader and astronauts John Glenn and Neil Armstrong, both Ohio natives. There have been tributes to the Ohio State Buckeyes football team and golfer Jack Nicklaus. This year, the sculpture was a space shuttle with a floating astronaut enjoying freeze-dried ice cream.
The sculpture honored the end of the shuttle program in the state that has produced more astronauts than any other.
"I think it's really cool, with the shuttle mission being over," said David Cunningham, an 18-year-old Ohio State University business student. "It keeps the program in a good light."
Nancy Walcutt, 60, a retired teacher from Lewis Center, Ohio, marveled at the butter cow during her recent visit to the fair.
"To put so much butter together and manipulate it in so many ways to come together and make a cow — the muscles and the veins and just the detail that goes into it," she said. "It's really skillful."
Associated Press writer Andy Brownfield contributed to this story from Columbus, Ohio.
Copyright 2011 The Associated Press.