The three-year proposed programme of research aimed to provide the ability to introduce precise genetic changes in the pig, or to obtain large numbers of genetically identical offspring. This would be achieved by nuclear transfer methods from cultured cells in which precise genetic changes are introduced before they are used as nuclear donors. This would enable the production of groups of genetically identical pigs from the same population in cultured cells, leading to financial and genetic gain in elite herds. There had previously been little attempt or success in developing methods for nuclear transfer in pigs, partly because the stage at which the genome of the embryo begins to control development occurs earlier in the pig than in the sheep or amphibians, thus making nuclear transfer more challenging to accomplish.