Suitable embryos are transferred non-surgically to the uterine horn of the recipient on the side of the corpus luteum. Donor and Recipient Aftercare Donors are commonly treated with PGF after collection of ova to cause a rapid reduction in the size of the ovaries which have been enlarged by the excessive number of corpora lutea, and to terminate an unwanted pregnancy should an occasional embryo not be flushed out. The donor should not be bred on the subsequent heat 3 to 5 days later. Cows can be superovulated at 2 month intervals for three treatments without major effect on reproductive performance or number of embryos produced. Recipients are handled as other pregnant cows.
Success depends on the quality of embryo preserved and the handling procedures.
The splitting of embryos is now a commercially available service. Sexing of the embryo is possible, however, the cost of equipment and time limit the practical use of the techniques. Commercial value of sexing would be greatest if only offspring from one sex were required.