The animals imported from Japan are guarded by off-duty Texas Rangers and kept away from American bulls that might contaminate their coveted gene pool. They were meticulously reared for 12 years before a single hamburger could be sold.

"We knew it was going to take a long time," said Calles, whose interest in ranching was sparked by a grandfather who raised cattle for export in northern Mexico.

Japanese cattle, which come in red and black varieties, are a closely guarded national treasure. Their beef, often called "Kobe beef" by American restaurants, commands staggering prices but is heralded by chefs and foodies for thoroughly marbled fat that gives the meat tenderness and rich flavor. On a 0-12 quality scale used to rate beef in Japan, where heavy fat marbling is preferred, Kobe rates a minimum nine points and Angus beef 4.5; Calles' animals rate around 7.5 to 8.5.

Through careful breeding and with the help of surrogate cows, Calles's tiny herd of 11 has grown to 5,000, the largest group of purebred Akaushi cattle outside Japan.

Source: Forbes