Obviously the most important thing necessary for your involvement in embryo transfer is selection of your donor female. In my opinion, the best donor from a productive standpoint is a 3-8 year old cow in production that has calved 60-90 days. Of course for the producer, it is best to identify cows that excel in some aspect for your situation whether that be phenotype, exceptional epd’s, show career, etc. You need to propagate a potentially marketable product.
Of course that is the ideal situation. Many of the animals we are presented to enroll in an embryo transfer program are not ideal. Expect results to be potentially less rewarding as the “strikes” against the donor female increase. By strikes, I mean age (virgin heifers and old cows), injury (stifle injuries most common), reproductive problems (non-breeders, calving injuries, adhesions both ovarian and uterine). Does that mean they won’t work? Not at all but expectations should be less for these particular animals.