Abstract
About 17,000 bovine pregnancies were produced by superovulation and embryo transfer in North America in 1979. The major use of these techniques is to increase the reproductive rate of valuable cows. Other applications include circumventing infertility, exporting embryos, and testing potential carriers for Mendelian recessive alleles. Cryopreservation of embryos is beginning to be used commercially, and sexing embryos before transfer may soon become routine.