How to buy registered beef embryos

By the RanchOS Global editorial team · Updated

In short: buy embryos you can verify. Ask for both parents' registration numbers and EPDs, the IETS grade and stage, how the embryos were produced (flush or IVF) and frozen, and the technician's certificates. Then plan your recipient cows before the embryos arrive, because recipients decide most of the result.

What you are buying

An embryo is a calf from a known registered sire and donor cow, carried by one of your own recipient cows. Judge it the way you would judge a bull: look at both pedigrees and both sets of EPDs. Check your breed association's rules for registering calves born from embryo transfer before you buy. Some associations require embryo or donor information to be reported before the calf can be registered.

The paperwork to ask for

Mississippi State University Extension notes that embryos may not be marketable without proper documentation. Ask the seller for:

  • The straw label details: the technician's IETS code, breed, the dam's and sire's registration numbers, the number of embryos in the straw, and the date.
  • Certificates of recovery and freezing from the embryo transfer technician, with freeze codes.
  • How the embryos were frozen (see below), so your technician knows how to thaw them.

Grade and stage

Embryos are graded with two numbers under the International Embryo Technology Society (IETS) system. The first number is the stage of development (1 to 9). The second is quality (1 to 4, where 1 is excellent or good).

  • Grade 1 and 2 embryos can be transferred fresh or frozen.
  • Grade 3 embryos are much less viable after freezing, so they are normally only transferred fresh.
  • Grade 4 embryos are dead or degenerating and are not transferred.

When you buy frozen embryos, ask for grade 1 or 2.

How they were frozen

  • Ethylene glycol (direct transfer): the most common method. The straw can be thawed and placed in the recipient directly.
  • Glycerol: less common. A trained embryologist has to thaw and rinse the embryos under a microscope before transfer.

Flush (MOET) or IVF

  • Conventional flush (MOET) embryos hold up well after freezing, which is why most frozen embryos sold between ranches are flushed embryos.
  • IVF embryos get more out of scarce semen and difficult donors. In several studies they gave pregnancy rates 10% to 40% lower than flushed embryos. The UGA Beef Team notes that the gap now appears smaller.

Ask which method was used. It matters most if the embryos are frozen.

What results to expect

Mississippi State Extension gives about 65% pregnancy for fresh embryos transferred at the right stage of the recipient's cycle, and about 55% for frozen-thawed embryos. The UGA Beef Team reports frozen embryos running about seven percentage points below fresh. Your own results will depend on your recipients, your technician and the embryos. Set up more recipients than you have embryos.

Getting your recipients ready

  • Condition and feed: keep recipients in good, steady body condition. The UGA Beef Team advises avoiding major diet changes in the 45 days before and after transfer.
  • Health: test recipients for enzootic bovine leukosis, Johne's disease, BVD, anaplasmosis and neosporosis, keep vaccinations current, and control parasites.
  • Check the reproductive tract before synchronization. A recipient without a corpus luteum on transfer day should not be used.
  • Synchronize recipients to the right day of the cycle with your technician's protocol, and keep them away from bulls.
  • Temperament: calmer recipients tend to have higher pregnancy, calving and weaning rates.
  • Technician: choose an embryo transfer technician who is an IETS member, and check references with other producers.

Questions to ask the seller

  1. What are the sire's and donor's registration numbers and current EPDs?
  2. Flush or IVF? Fresh or frozen, and frozen in ethylene glycol or glycerol?
  3. What are the IETS grade and stage of each embryo?
  4. Can you send the technician's freezing certificate and the straw labels?
  5. Have embryos from this mating produced calves already?
  6. How will the embryos ship, and who pays for the tank?

See also IVF vs. conventional flush: producing embryos to sell and What are EPDs. On RanchOS Global, donor cows show their pedigree and EPDs on their own page, and you can contact the ranch directly about embryos.

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