Limousins for the six reported market end points still exceeded the average of the other two breed groups by up to one-fifth. Live weight and daily live weight gain are the simplest and most common of all traits to be measured and reported, which continues to mask Limousin's superior saleable meat production efficiency. Breed differences are expected to have reduced since the USMARC studies in the 1980s and 1990s because of the wide-scale introduction and use of performance recording and genetic improvement programmes. The reduction in yield reported for Limousins is possibly a result of the loss of French Limousin content and of F94L myostatin mutations from the US purebred population, which would be an expected result of the purebred grading up process practiced there. Earlier USMARC studies are reported to have evaluated high content pure French Limousins. Breed comparison studies of performance-tested bulls report Limousin's more efficient conversion of feed into live weight and confirm the breed's slower live weight gain when compared with other beef cattle breeds. Limousins generally have lower levels of intra-muscular fat (marbling) and subcutaneous fat when compared with British breed cattle grown in similar conditions. Marbling, together with tenderness and flavour, has been associated with eating quality in some countries, and attracts a higher quality grading with associated premiums, although the link between marbling and palatability is not universally supported. In some countries, Limousin's lean, tender meat is considered to be of outstanding quality and marketed through specialist outlets. Beef producers targeting the higher marbling specifications of some markets, but who have concerns over the poorer feed conversion efficiency and yield associated with higher marbling British breed cattle, use Limousin sires over British breed cows, or British breed sires over Limousin cows, in crossbreeding programmes that aim to achieve a balance between the different and conflicting production demands. Crossbreeding with Limousins Crossbreeding increases production efficiency because of hybrid vigour, and allows complementary traits of parents to be combined to produce progeny better suited to different environments or markets. Crossbreeding through the use of Limousin terminal sires in purebred British breed cow herds allows the complementary traits of higher marbling and fat cover provided by the British breed cows, and required or preferred by some markets, to be combined with the higher yield and feed conversion efficiency of Limousin sires. Crossbred cows produce up to, and in some cases in excess of, 20% more weaned