Sustainable Agricultural Systems for the Northern Great Plains

Interpretive Summary: There is a growing interest in beef from animals finished on pasture. This research conducted three types of chemical analyses relevant to nutrition to study more than1500 compounds in the meat of Black Angus cattle from two common commercial US beef finishing systems (grass-fed on pasture and grain-fed in a feedlot). We found that 907 out of 1575 profiled compounds differed in abundance between grass-fed and grain-fed beef samples. Grass-fed beef had higher levels of potentially beneficial compounds , while grain-fed beef had higher levels of other potentially beneficial compounds. This indicates that feeding some grain (by-products) could be beneficial. Grass-fed beef samples also had lower markers of oxidative stress and improved mitochondrial function compared to grain-fed animals. Two potential metabolites of antibiotics, were only observed in grain-fed beef. Pasture-finished cattle displayed improved markers of metabolic health and potentially beneficial compounds for consumers. Our findings, however, do not indicate that grain-fed beef is unhealthy. It remains to be determined in randomized controlled human feeding trials whether observed differences have an appreciable effect on human health.