"Here's a video, not the best but it'll do," she wrote.
Simpson's bond with Lilac began when she was 11 years old and her brother suggested she ride the six-month-old calf after her parents would not give her a horse, she told the New Zealand Herald.
"I've always loved adventure and stuff like that. I wanted a horse and I couldn't have one," Simpson said. "We just jumped on and away we went, there was no training. And she's got better the more I ride her."
Simpson attempted to ride other cows but all except for Lilac and one other cow bucked her off their backs.
Now Lilac can jump over obstacles about four feet high, including fallen trees, but only when she's in the mood, according to the Guardian.
"She is a cow and I can't expect her to ride like a horse. Without a bit of prodding she wouldn't really do anything, she has a very chilled-out nature," Simpson said.
Lilac refuses to wear a saddle, but Simpson is content with riding the special cow bareback around her farm rather than taking her unique abilities to show-jumping competitions. ]
"I don't think she would behave if we took her anywhere but home. And I don't need to compete. She is more special than a horse, more rare," she said.
