Diet has a large impact on the fatty acid composition of muscle lipids in cattle (Scollan et al., 2006). Grass relative to concentrate feeding increases the content of n-3 polyunsaturated fatty acids (PUFA) resulting in a low n-6:n-3 PUFA ratio and also increases the concentration of the antioxidant, vitamin E, in the meat. Ruminally protected plant lipids enhance PUFA content very significantly resulting in beneficial P:S and n-6:n-3 ratios, but without extra antioxidant input can lead to lipid oxidation and reduced colour shelf life. This study considered the effects of finishing steers (1) outdoors on grass ± concentrate versus (2) indoors on straw/concentrate ± a protected lipid supplemental with one of two levels of vitamin E on the sensory quality and lipid and colour stability of the loin muscle.