"The first few days she was throwing herself at the fence, " Mr. Grell says.

WSJ: Ninja Cow Had an Excuse for Udderly Unbovine Behavior

Mr. Grell and his friends set off the next morning, two on horseback and one on foot.

WSJ: Ninja Cow Had an Excuse for Udderly Unbovine Behavior

Now, Ninja Cow, a fairly young Black Angus, is starting to calm down in Mr. Grell's small pasture.

WSJ: Ninja Cow Had an Excuse for Udderly Unbovine Behavior

With the help of a veterinarian, she got in touch with Mr. Grell and two of his buddies.

WSJ: Ninja Cow Had an Excuse for Udderly Unbovine Behavior

"It isn't like rodeo team roping, where the faster you go the better it is, " Mr. Grell says.

WSJ: Ninja Cow Had an Excuse for Udderly Unbovine Behavior

Terry Grell, a 55-year-old contractor, was one of those who called in.

WSJ: Ninja Cow Had an Excuse for Udderly Unbovine Behavior

"I wouldn't say she was wild, but she was really smart, " says Neil Johnson, 52, who joined Mr. Grell on his trusty horse Booger.

WSJ: Ninja Cow Had an Excuse for Udderly Unbovine Behavior

Ultimately, Mr. Grell chased the cow down a hill.

WSJ: Ninja Cow Had an Excuse for Udderly Unbovine Behavior

"If you're interested in getting this cow caught, you can give me a call, " said Mr. Grell, who says he learned roping years ago from an old cowboy he met while working at a feed lot.

WSJ: Ninja Cow Had an Excuse for Udderly Unbovine Behavior