Move over Clint Eastwood. The winning slogan from Clover Stornetta Farm?s billboard contest will have the company?s bovine star boasting, ?Clo Ahead, Milk My Day.?

The pun, to be used in the Petaluma dairy processor?s advertising program, earned a Rohnert Park couple $5,000 Thursday. Their idea was judged tops from more than 12,000 entries sent in from across the United States.

Daniel Judd and Andrea Duszynski won for their humorous takeoff on a line from Eastwood?s 1971 classic ?Dirty Harry? ? ?Go ahead, make my day.?

The couple came up with the idea after Judd?s mother encouraged them to write a winning contest slogan for Clover?s mascot, Clo the Cow.

?We brainstormed for a couple of days,? said Judd, a journeyman welder who grew up in Petaluma. ?We saw the ad in the newspaper and we knew we had to go after it.?

Their slogan will appear soon on a billboard on Highway 101, said Joanie Benedetti, Clover Stornetta?s director of marketing. The new advertisement also will be included in an upcoming book that will feature more than 140 Clo billboards from the past four decades.

Over the years Clo has become one recognizable Sonoma County cow.

?I think Clover has been an iconic image of the dairy industry,? said Lex McCorvey, executive director of the the county?s Farm Bureau. Even county visitors have noticed the billboard puns ?and gotten a chuckle.?

Behind the bulky white mascot is an independently owned company with 250 employees and $120 million in annual revenues.

Clover Stornetta is the largest dairy processor in the North Bay, buying milk from 30 local dairies. Most of the company?s sales take place in the Bay Area, but its reach extends to the Oregon border, the Sierra Nevada, Southern California and parts of Nevada and Arizona.

The company is one of a small number of independently owned processors left in California. Many competitors have been gobbled up by huge national processors, but Clover officials said Thursday they plan to hold onto this family-run business.

?We?re having a lot of fun doing what we?re doing,? said Clover Stornetta President Marcus Benedetti.

His grandfather, Gene Benedetti, led the partnership that founded the company in 1977. Before that, Clo was a mascot of Clover?s predecessor, the California Cooperative Creamery.

This latest billboard contest comes 20 years after the company?s first one, a competition that drew 6,000 entries. The winner from 1989: ?Tip Clo through your two lips.?

This time, with double the entries, it took about four days to narrow the field to 20 top selections, said Joanie Benedetti. Clover Stornetta and its ad firm, VeVa Communications of Santa Rosa, shipped off the 20 ideas for judging to three ad agencies in Los Angeles, San Francisco and Richmond, Va.

On Thursday Clover Stornetta awarded a second-place prize and $2,500 to Meagan Finnerty of Santa Rosa for her slogan: ?You Had Me at Clo.? Third place and a $1,000 prize went to Justin DeFreitas of Berkeley for his line: ?Heifer Lasting Love.?