The Beef Nutrient Density Project analyzed more than 300 beef samples from North American farms and supermarkets to see how grass- and grain-fed systems affect nutrients in meat, particularly fatty acids and minerals. On average, grass-fed beef contained higher amounts of omega-3 fatty acids and minerals, such as iron, calcium, copper, and selenium, especially when cattle were rotationally grazed and finished on pastures with a wide variety of plants. However, there was substantial variation within both systems. Some grain-fed samples had omega-3 and mineral levels that overlapped with or were higher than grass-fed samples, particularly when feedlot diets used less grain and shorter finishing periods and when grass-fed cattle grazed less plant-diverse pastures. These findings highlight the complexity of beef nutrition and suggest that simplified labels like “grass-fed” or “grain-fed” may not fully capture nutritional differences. Providing more detailed information on nutrient content (for example, front-of-package labeling of omega-3 content and/or an omega-6 to omega-3 ratio) could help consumers make informed choices. Producers can use our study insights to refine management practices associated with elevated concentrations of omega-3 fatty acids and minerals in beef.

Read the full article in the Journal of Animal Science.