top 10 bulls out of this testing, and the best natural service bulls, are then evaluated. Cows are inseminated to produce 60 to 80 calves per bull tested, which are in turn evaluated. Male progeny go to a station in Pépieux in the south of France, where they are fed a ration of corn silage before being slaughtered at the age of 16 months. In addition to evaluations of growth and conformation in the live animals, carcases, including fat composition, are evaluated. The best bulls identified in progeny testing are formally given the award Young Beef Cattle (in French Viande Jeunes Bovins, abbreviated to JB). Female progeny go to a test station in Moussour in Corrèze, where they are inseminated with the same bulls and calve at two years in confinement before being put out to pasture with their calves. The test station evaluates weight, growth, morphology, fertility, calving ability and milking ability in order to assess their maternal qualities. The best bulls following the tests on their daughters are identified as Maternal Qualities (in French Qualités Maternelles, abbreviated to QM). The qualifications RR and RRE are recorded with an animal's description in sales' catalogues and other promotional literature. As a further aid to purchasers of French Limousin genetics, additional qualifications provide a guide to the greatest likely production benefit based on an animal's genetics estimated from on-farm progeny testing. The qualifications are aligned with French market specifications for Limousin beef: VS – awarded to sires recognised or recommended for weaner production. VB – awarded to AI sires recognised or recommended for vealer production. JB – awarded to AI sires recognised or recommended for general beef production. QM – awarded to AI sires recognised or recommended for breeding stock production. M – awarded to AI sires recognised or recommended for both general beef and breeding stock production. P – awarded to females recognised or recommended for the production of early developing progeny. T – awarded to females recognised or recommended for the production of late developing progeny. Genetic basis for muscling in Limousin cattle The Limousin cattle breed has been popular in France for more than two centuries because of its meat qualities and the breed's production efficiency. Since the early 1990s scientists have quantified these breed characteristics in comparisons with other breeds, and identified a natural variant of the myostatin gene found in Limousins which has a significant influence