07/30/2008 at 04:30 PM EDT
When she isn't recording blockbuster country hits, raising three daughters, cooking up a storm or being the glamorous wife of Garth Brooks, Trisha Yearwood is ... drinking milk.
Yearwood, whose cookbook hit No. 3 on the New York Times Bestseller list in April, is the latest celebrity to sport the white mustache in her "Got Milk?" ad campaign which debuts in August magazines.
"I grew up on a farm, so I've been singing milk's praises my whole life," the Georgia-raised Yearwood, 43, says in the ad.