Different sources of animal feed have different profiles of natural stable isotopes. For example, C3 plant-driven feeds (including natural pasture, grass silage, soybean silage) have a significantly different carbon-isotope ratio to C4 plant-driven feeds (including maize silage). These differences can underpin tests to verify premium claims such as “grass fed beef”. Similar price premiums apply to yak meat. In this paper (purchase required) the authors bult a multivariate model which discriminated between grass-fed and maize-fed yak meat by stable-isotope ratio analysis (C, N, S, O, N) of the muscle and stable-isotope ratio analysis (C) of six selectively extracted fatty acids. As with all such models, its use is restricted to the species, geographic regions and husbandry practices included in the reference database but it proves the concept.
Photo by Jasper Garratt on Unsplash
Comments