Abstract. From the information provided by the National Farm Accountancy Data Network (FADN), referred
to the sheep orientation for years 1987, 1990, 1994, 1999 and 2002 (added information of the sample of the
sheep farms), the structural, economic and productive characteristics of representative meat and milk sheep
systems of nine Spanish regions are described. Indices of animal productivity are elaborated (livestock
capital), assimilable to the technical efficiency. For the considered regions, the differences in productivity, its
evolution during the period 1987-2002 and its possible relationship with some characteristics of farms are
analyzed. Considering that the productivity is a long term determinant of standard of living for sheep farmer,
we try to advance a hypothesis related to sources of knowledge of this sector and role of technological
change.