Grass-fed vs. grain-fed: What’s the difference?
Next time you shop for groceries, you can find a wide variety of choices at the meat counter, including grass-fed beef, an alternative to conventionally farmed beef.
Grass-fed cattle spend their entire lives grazing from pastures. Here in Iowa and the Upper Midwest, grass-fed cattle are also fed hay in the winter, when the grass isn’t growing and pastures are covered in snow.
Grain-fed, or conventionally farmed cattle also spend the majority of their lives grazing from pastures. When the cattle are about 18 to 22 months old, they also eat a balanced diet of corn, local feed ingredients, and hay or forage in the feedyard.
Iowa - the nation’s top corn producing state - is recognized worldwide for its USDA Prime-grade, corn-fed beef.
Is grass-fed beef healthier?
Food marketers and health influencers often claim that grass-fed beef provides more omega-3 fatty acids than grain-fed beef. Omega-3 fatty acids are considered “good” fats for heart health.
Studies have shown that grass-fed beef has more omega-3s than conventional grain-fed beef.
However, that doesn’t mean grass-fed beef is a significantly better source of omega-3s than grain-fed beef, says Ruth Litchfield, an Iowa State University nutrition scientist.
A 3-ounce serving of grass-fed ground beef has about 0.015 grams of omega-3 fatty acids, according to the U.S. Department of Agriculture’s National Nutrient Database. “So 100ths of a gram of omega-3s,” Litchfield notes. (For a real-world visual, 1 gram is equal in size to one raisin.)
In comparison, a 3-ounce serving of conventional ground beef has about 0.003 grams of omega-3s, according to the National Nutrient Database.
Even though conventional beef has less omega-3s than grass-fed beef, it isn’t a clinically significant difference to human health, Litchfield says.
What is a good source of omega-3s?
Beef in general – whether grass-fed or grain-fed – isn’t considered a good source of omega-3s, Litchfield explains.
Seafood, in comparison, is an excellent source of omega-3 fatty acids. A 3-ounce serving of wild-caught Alaskan salmon has about 1.5 grams of omega-3 fatty acids, much greater than the 0.015 grams of omega-3s in grass-fed beef, according to the National Nutrient Database.
“You would have to consume 100 times the amount of (grass-fed) ground beef to get the same amount of omega-3s as the similar portion of salmon,” Litchfield says. “So in the scheme of things, you can’t eat enough (grass-fed beef) to make a significant impact on your (omega-3) intake.”
What are the nutritional benefits of beef?
However, all beef – grass-fed and grain-fed - is considered an excellent source of many other micronutrients, including B12, iron, zinc and high-quality protein, which are essential for human health, Litchfield says.
The USDA also recommends lean beef as part of a heart-healthy diet in its MyPlate dietary guidelines.
So whether it’s grass-fed or grain-fed beef, both are nutritious choices, Litchfield says.
Iowa farmers remain committed to continuous improvement to ensure the safety, nutrition and sustainability of the foods they grow for all of us.
To learn more about how farmers work to ensure meat quality, food safety and animal well-being, visit the “Real Farmers. Real Food. Real Meat” website.