To determine whether circulating levels of blood isoprostane can be utilised as an effective biomarker in prime lambs to predict changes in the colour and/or flavour stabilities of meat post-slaughter; the circulating level of blood isoprostane was determined in 84 lambs finished on four different finishing diets (lucerne, ryegrass, commercial feedlot ration and a combination of rye grass and commercial feedlot ration). The circulating levels of isoprostane for each animal was then correlated with traditional meat quality measurements for colour and/or flavour stabilities. This included lipid oxidation levels in meat (i.e. thiobarbituric acid reactive substances (TBARS) analysis), muscle vitamin E content and meat colour redness and brownness as determined by HunterLab.