Grass-fed vs Grain-fed
The research paper below, titled ‘A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef’, shows a significant difference in the ratios of omega-6 to omega-3 fatty acids when comparing grass-fed to grain-fed beef.
Growing consumer interest in grass-fed beef products has raised several questions about the perceived differences in nutritional quality between grass-fed and grain-fed cattle. Research spanning three decades suggests that grass-based diets can significantly improve beef’s fatty acid (FA) composition and antioxidant content, albeit with variable impacts on overall palatability.
Grass-based diets have been shown to enhance total conjugated linoleic acid (CLA) (C18:2) isomers, trans vaccenic acid (TVA) (C18:1 t11), a precursor to CLA, and omega-3 (n-3) FAs on a g/g fat basis. While the overall concentration of total SFAs is not different between feeding regimens, grass-finished beef tends toward a higher proportion of cholesterol-neutral stearic FA (C18:0) and less cholesterol-elevating SFAs such as myristic (C14:0) and palmitic (C16:0) FAs.
Several studies suggest that grass-based diets elevate precursors for Vitamin A and E, as well as cancer-fighting antioxidants such as glutathione (GT) and superoxide dismutase (SOD) activity, as compared to grain-fed contemporaries. Fat-conscious consumers will also prefer the overall lower fat content of a grass-fed beef product.
However, consumers should be aware that the differences in FA content will also give grass-fed beef a distinct grass flavour and unique cooking qualities that should be considered when transitioning from grain-fed beef. In addition, the fat from grass-finished beef may have a yellowish appearance from the elevated carotenoid content (precursor to Vitamin A). It is also noted that grain-fed beef consumers may achieve similar intakes of both n-3 and CLA by consuming higher-fat grain-fed portions (Daley, et al. 2010).