Iowa Senate candidate Joni Ernst (R) released her first TV ad Tuesday, a 30-second commercial in which she vows to cut wasteful spending by drawing on her past.

"I grew up castrating hogs on an Iowa farm. So when I get to Washington, I'll know how to cut pork," Ernst says in the commercial. At the end of the ad Ernst concludes, "Washington's full of big spenders. Let's make 'em squeal."

A state senator, Ernst is part of a crowded GOP field running for the seat of retiring Sen. Tom Harkin (D). While the Republican race is wide open, Rep. Bruce Braley (D) is set to coast to the Democratic nomination.

When asked about the size of the ad buy, Ernst spokesman Derek Flowers declined to say how much money the campaign was spending. But he suggested it was limited. A Democratic tracking the ad buy later said there was only $7,000 behind it.

"Initial run is just cable in the Des Moines market with plans to expand in coming weeks," Flowers wrote in an e-mail.

Mitt Romney recently endorsed Ernst, calling her a "mother, soldier and proven conservative." Ernst is a lieutenant colonel in the Iowa Army National Guard.