The propagation of genes from farm animals of superior genetic merit is presently most rapidly achieved by superovulation and embryo transfer. Although these procedures increase the number of offspring from superior females, genetic uniformity and predictability are not guaranteed because of the diversity introduced by genetic recombination at meiosis. To overcome this problem, techniques that generate identical embryos from a single founder have been devised. Embryo splitting and blastomeres separation represented the first approaches to embryo multiplication, but both these techniques are severely limited by the very small clone size which rarely exceeds two offspring. Nuclear transplantation has the potential to produce far larger number of identical embryos but is technically more difficult and involves three separate procedures. Firstly, a source of nuclei, or so called caryoplasts, in an appropriate undifferentiate state is required. Secondly, a supply of enucleated host cells or cytoplasts is essential for the support of the transplanted nucleus.