The bulk of the feat aside, it may seem simple to transplant an embryo from one cow to another, but it is a very complex procedure. When the operation was first performed in 1953, i t was hailed as a remarkable achievement both in veterinary medicine and in the larger field of reproductive science. In the 1953 cxperimcnr, the embryo was removed from one cow that had conceived in the normal way and was then transplanted into another cow, where the embryo matured and was delivered in good health. The advantage to veterinarians and breeders was that high7quality cattle could be used for conception and spared the rigors of pregnancy by having their burden transferred to cows genetically unsuitable for breeding.

For researchers in the field of human rcproduc-- tion, the cow-embryo transplant was a major step in the development of in-vitro fertilization (in vitro meaning...