Embryo transfer as a reproductive management tool

Regardless of whether generated by superovulation (otherwise called multiple ovulation – embryo transfer; MOET) or by in vitro production (IVP), the most common purpose of transfer of cattle embryos today is for genetic improvement. The advent of genomics means that genetically-superior females can be identified with acceptable accuracy and these females can be used to produce up to 100 or more embryos from a cow or heifer each year. Embryo transfer can also be used to rapidly establish a herd of high-producing animals, as exemplified by the large numbers of embryos exported from North America to other countries to establish high-yielding dairy herds. Production of embryos in vitro is also an effective means of utilizing sexed semen because one straw of sexed semen can be used to produce multiple embryos in vitro. The pregnancy rates following transfer into recipients is similar between cows receiving embryos produced sexed semen and those receiving embryos produced with conventional semen (Xu et al., 2006; Rasmussen et al., 2012) ...