Published online by Cambridge University Press: 27 March 2009
The Southdown is a terminal sire breed producing about 205 registered rams for commercial use in Britain each year. It is strongly associated with its native area of Sussex, with an hierarchical breed structure very similar to that of 30 years ago. The number of breeding ewes has declined from 5475 in 1957 to (minimum estimate) 1202 in 1985.
French and New Zealand imports in the last 20 years have resulted in present-day British Southdown breeding rams being, on average, only 76% of British descent. If further importations are to be made, semen from rams without foreign blood should be taken for storage first, in the interests of genetic conservation.
The required production of Southdown rams for commercial purposes is achieved with a rather small population size. It would be misleading to describe the Southdown as a ‘rare breed’ without taking account of its commercial function and breed structure.