Grass-fed beef is nutritionally superior to its more prevalent and less expensive grain-fed counterpart, according to research and nutrition experts.

Grass-fed beef is lower in overall fat, has a healthier combination of fatty acids, has more vitamins and has more cancer-fighting antioxidants than grain-fed beef, according to the summary of a Nutrition Journal article from 2010 that summarized three decades worth of research.

But to maximize the favorable fatty acid profile, including the ratio of omega-6 fatty acids to omega-3 fatty acids, and to guarantee the elevated nutritional content, cattle should spend their entire lives eating only grass and pasture diets, according to the study.

In other words, a mostly grass-fed cow isn’t as good as an exclusively grass-fed cow.

Grass to grain

Cows traditionally foraged on grass from pastures. But after World War II, this country had a surplus of corn, allowing the development of the feedlot system in which cattle could eat grain and gain weight faster, said Scott Duggan, an agricultural science teacher at Sisters High School. The system kept farmers from going bankrupt and helped feed a growing nation.

“We couldn’t have all the fast-food businesses without it,” Duggan said.

When exclusively grass-fed, cattle can take up to two and a half years to reach slaughter weight, said Duggan, who also works summers on his parents’ DD Ranch near Terrebonne, where they raise grass-fed cattle. Feeding cattle a higher-carbohydrate diet of grains — mainly corn — can fatten them to their slaughter weight in 18 months, Duggan said.

Duggan said it’s unnatural. The altered diet for the cows carries along the food chain and affects the human diet. Since scientists have realized that the nutritional value of beef drops when cows are corn-fed, there’s been a movement toward returning to that traditional way of feeding cattle.

Nutritional differences

Here are some of the nutritional differences, as explained by Shelley McGuire, a national spokeswoman for the American Society for Nutrition and associate professor of nutrition at Washington State University:

Fat:

Pasture-fed animals are leaner than grain-fed animals. The difference is reflected in the fat content of the muscle, the part we eat. Gram-for-gram, grass-fed beef has less fat, known as marbling, than beef from a feedlot.

This also means lower saturated fats and cholesterol, a good idea for people at risk for obesity and heart disease.

“Of course, flavor and juiciness are directly related to marbling, so there’s a trade-off here,” McGuire said.

Calories:

The difference in fat content is directly linked to lower-calorie content. A steak from a grass-fed animal will have fewer total calories and more protein than the same size steak from a corn-fed animal.

Omega-3:

(Fatty acids linked to improved heart health and mental health.)

Forages such as grass and clover generally have more omega-3 fatty acids than grains such as corn, McGuire said, so when cattle eat those things instead of grains, it results in greater omega-3 levels in the meat. But, she said, because there’s less fat in the grass-fed beef, there’s probably a comparable amount of omega-3 in a similar size steak of both types. Fatty acid profiles (such as omega-3 vs. omega-6) vary depending on when the animal is slaughtered. Bottom line, she said: Beef shouldn’t be a person’s primary source of omega-3. Try fish.

Conjugated linoleic acid:

(CLA is a potent anti-carcinogen found almost exclusively in ruminant fats, such as beef and butter.)

Bacteria in the rumen — a stomach compartment in a cow — produce more CLA when cattle have access to grass fibers. So, grass-fed animals tend to have more CLA than their grain-fed counterparts. However, as with omega-3 fatty acids, there’s a bit of variability.

“You may get slightly more CLA if you eat a grass-fed steak, but if you want to make sure you get enough CLA you should probably use butter instead of margarine on your potato,” McGuire said.

Vitamin E:

There is some evidence that vitamin E content of grass-fed animals is greater than that of grain-fed animals, although the literature is somewhat inconsistent, she said.

Buyer beware

Grass-fed beef can be purchased in Central Oregon directly from ranches, at farmers markets, from some retail stores and centraloregonlocavore.com, an online local food market.

When a retailer sells beef that is marketed as grass-fed, it typically means that the cattle ate only grass or forage for their entire lifetime. But sometimes cattle that ate mostly grass but were fed grains during the final months of their lives are marketed as grass-fed, said Duggan.

Some in the industry call exclusively grass-fed cows “grass-finished,” indicating that the cow ate only grass and forage until the day of its slaughter and was never fed any grains.

The distinction is important, Duggan said, because nutrition benefits of grass feeding can diminish if the cow is fed grain in those final months of life. If the meat doesn’t say grass-finished, ask the rancher or the retailer to specify if the cattle ever ate grain, he said.

“ ‘Grass-finished’ and ‘grass-fed’ are sort of interchangeable (terms) as far as the USDA is concerned,” said Jim Males, a professor of animal sciences at Oregon State University in Corvallis. Both imply, but don’t guarantee, an exclusively grass-fed cow.

At this point, there is no federal requirement that regulates the term grass-fed, although there are some certifications — through the U.S. Department of Agriculture or the Food Alliance, a Portland-based voluntary certification program, for example — that can help a consumer know the claim has been verified.

Not all grass-finished beef producers go to the expense of getting certified. Correspondingly, not all beef marketed as grass-fed was actually grass-finished.

At Whole Foods Market in Bend, according to meat team leader Derek Rusaw, “grass-fed” label means the cattle were raised on grass only, and never fed grain.

The store also sells “natural” beef, which is from pasture-raised cattle that had grain introduced later in their lives. They are considered a “grain-finished” beef.

Whole Foods sells organic beef, which was also “grass-finished,” Rusaw said.

Organic doesn’t always mean grass-finished, Duggan said, although there’s often overlap.

If a package of beef doesn’t claim the product was either grass-fed or grass-finished, the cow was grain-fed. Most beef purchased at grocery stores was finished on grains, which could be a mix of corn, barley and others.

Of course, grass-fed beef will cost more than conventional beef, mostly due to increased costs of raising grass-fed cattle.

But Duggan said there’s a market for the higher-priced product, and it’s a viable business for his family.

“People started asking for it. Also, when a cow is grain-fed in a feedlot, it’s had hormones injected and been fed antibiotics. People are asking for hormone-free beef,” Duggan said. DD Ranch cows are not given hormones or antibiotics, he said.

“People want health benefits and also have a problem with the feedlot confinement feeding issue,” he said, speaking of the environment in which feedlot cattle live.

“That whole grass-finished market is growing every year,” he said.

Local beef

Here are some regional ranches that retail grass-fed beef to interested consumers:

• DD Ranch, Terrebonne, www.ddranch.net, 541-548-1432

• Celtic Cow Ranch, Paulina Mountains, www .celticcowranch.com/beef .htm, 541-350-3571

• Dancing Cow, Prineville, 541-306-0226

• Painted Hills Natural Beef, Fossil, www.painted hillsnaturalbeef.com, 541-763-2333

• Rudio Creek Ranch, Kimberly, www.rudio creekranch.com, 503-798-9731