(Joni Ernst/YouTube )

If conservative U.S. Senate candidate Joni Ernst gets a chance to come to Washington, she's promising to make it hurt.

In her first television campaign ad, Ernst, who is running in a crowded and competitive Republican primary in Iowa, not-so-subtly threatened to castrate Washington spendthrifts.

And she has the credentials to back up her warning.

"I grew up castrating hogs on an Iowa farm. So when I get to Washington, I'll know how to cut pork," she says in the 30-second spot, as a pig squeals in the background.

Ernst, a member of Iowa's National Guard, who is vying for retiring Democratic Sen. Tom Harkin's Senate seat, is one of five GOP candidates struggling to gain a foothold ahead of the June 3 primary.

She's running, in part, on her record as a fiscally conservative state senator - a legacy she hopes to continue in Washington.

"Washington's full of big spenders," Ernst says in the ad. "Let's make 'em squeal."