SENDAI – More than 500 cattle paraded through a ring in the Tohoku region for the “Wagyu Olympics” to win prizes and recognition as the most fertile — and mouth-watering — examples of wagyu beef, increasingly popular among foodies around the world.

The six-day contest that ended Monday (and which is held every five years) saw breeders of wagyu, prized by gourmet fans for its luscious marbling, compete for fame in categories such as best beef cattle, best bull and most fertile cow.

“I really can’t believe it, I’m so happy,” said 69-year-old Tadanao Sato, who claimed a trophy and bragging rights for nurturing Fumiayame, which won top prize for her beauty and high fertility.

Fertility is judged by the shape of the cow’s shoulders, its toned legs, and the “topline,” or the flatness of the back.

Beef quality is judged by the cattle’s fat marbling and leanness.

Overseas demand for wagyu, which means “Japanese beef,” has soared since widespread import bans were lifted more than a decade after an outbreak of mad cow disease in 2001.

In 2016, beef was Japan’s top export in the agricultural and livestock category, raking in ¥13.6 billion ($125 million).

“These last few years, the boom in Japanese food, as well as widespread praise for the high quality of wagyu, have caused overseas demand to grow rapidly,” said Toru Takano, an official of the National Federation of Agricultural Co-operative Associations. “We have been, and will try bit by bit, to open up wagyu markets overseas.”

Though “seed cattle” winners at the event, such as Fumiayame, go home to be pampered and produce future generations of winners, the beef division winners are slaughtered the day after the judging and are promptly frozen and auctioned at the Olympics.

The most expensive beef went for ¥54,001 per kilogram.