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After a first comparison of various prolific breeds crossed with Barrichonne du Cherre (BC), successive generations of Romanov × BC crossbreds were studied on experimental flock, in a second comparison. There was no difference among generations F-1 to F-4 regarding essential factors of numeric productivity in ewes. The INRA 401 dam line originated in the resulting population, which has appeared to be stable in main production traits. Since 1980, it has been subjected to a closed flock selection for prolificacy and milk production. Meanwhile, rams have been used on farms for intra-flock replacement of F-1 ewes. There is no difference in performances between G-1 (INRA 401 ram × F-1) and contemporary F-1, born in the same flock, and submitted to the same breeding methods.