DENVER » The nation’s buffalo ranchers have no catchy marketing slogan about what’s for dinner, and no big trade association budget to pay for making one up.

What they have these days are people like Joe and Matt Gould, an ambitious father-and-son team from western Kansas who branched out after 100 years of traditional cattle ranching by their family, and bought their first buffalo herd last year.

The Goulds, with 40 animals as a start, made their first delivery of buffalo meat, also known as bison, to friends here in Denver last week. They are opening a themed restaurant on the Kansas-Colorado border supplied by the ranch, and planning bison hunts for tourist-visitors.

"People want the high omega-3s," which are healthy fats, said Joe Gould, 61, as he scribbled notes at a mentoring session for buffalo-ranching newcomers at the National Bison Association’s winter conference at a hotel here last week.

With prices and American consumption of buffalo at all-time highs — though still minuscule in volume compared with beef, chicken or pork — a new chapter is clearly beginning for one of the oldest animal-human relationships on the continent, dating back millennia before the first Europeans arrived.

New ranchers are coming in. Older ranchers are straining to build up herds, holding back breeding females from slaughter and thus compounding what retailers say is already a supply crunch. Buffalo meat prices, meanwhile, have soared — up about 28 percent last year for an average rib-eye steak cut, according to the federal Department of Agriculture.

At Tony’s Market here in Denver, that surge is even steeper, up 25 percent just last week for a New York strip buffalo steak, to $24.98 a pound, $10 more per pound than premium beef for the same cut.

What happened, producers and retailers say, is that the buffalo, the great ruminant of the Plains — once endangered, now raised on ranches by the tens of thousands — has thundered into an era of growing buyer concern about where food comes from, what an animal dined on and how it all affects the planet.

Trendsetting consumers and restaurants on the East and West Coasts caught on. Grass-fed, sustainable and locally grown, obscure concepts to most people 15 years ago or so when the buffalo meat market first emerged, became buzzwords of the foodie culture. Nutritional bean counters, obsessing over lipid fats and omegas, found in buffalo a meat they could love.

"For the last two years, it’s been one of the fastest-growing categories in our meat department," said Theo Weening, the global meat coordinator for Whole Foods Market, one of the nation’s largest retailers of buffalo at its chain of stores.

Weening said buffalo benefited from a kind of synergy: Customers started embracing the idea of grass-fed beef, and from there it was a short leap to bison. "Both categories went hand in hand," he said.

But this new moment, buffalo ranchers and retailers say, is also loaded with risk that growth could come too fast or prices could surge so much that buyers or retailers back away. It is also spiced with a debate about what people really want.

Many of the new ranchers, like the Goulds, say the future of buffalo can be summed up by one term: grass-fed. Feeding animals only on grass, with no grain in their diet at all, is more natural for the animal and produces the kind of low-fat, environmentally sustainable product that they say best competes with beef for a place on the nation’s dinner table.

Many veteran ranchers, though, say that what consumers and retailers really want is consistency — one cut of buffalo tasting about the same as the next in both flavor and texture. And only grain-feeding, with some grain — often corn — in the diet in the last months before slaughter, can do that, they say.

Crucially, they say, grain-finished buffalo is what most people have probably tasted, bought at Whole Foods or off a restaurant menu. Purely grass-fed buffalo, they say, is more difficult to find and can vary in taste and tenderness from region to region and season to season. However it is raised, buffalo meat has much less fat than beef.

But with all the hand-wringing and hope about the future, the fact remains that buffalo is still barely a footnote. The average American ate about 65 pounds of beef last year but not even a Quarter Pounder’s worth of bison, according to the Bison Association.

The numbers of animals in the food chain reflect that disparity — about 70,000 buffalo slaughtered for their meat last year, according to the association, compared with more than 125,000 cattle every day.

But for newcomers like the Goulds, Lesson 1 is that buffalo are not anything like cattle.

While cattle can be easily herded along, their wild genes muted by generations on a treadmill to the slaughterhouse, buffalo might decide to turn and charge. When they do, they can outrun a track star, up to 30 miles per hour.

And while a cattle herd will usually respect a fence, a buffalo herd will not.

"We’ve figured out some things already, mostly by doing them incorrectly," said Matt Gould, 32. "But it’s a pretty steep learning curve."

© 2011 The New York Times Company