Embryo Transfer: How Top Cows Came to Produce Many Calves

What Is Embryo Transfer in Cattle?

Embryo transfer moves an early embryo from a donor cow into a recipient cow, which carries the calf to term. The donor is chosen for her genetics, the recipient for her ability to carry and raise a calf. Because a donor can be treated to release several eggs at once, a single outstanding female can contribute many calves in the time natural breeding would give her one.

The idea is simple, and the practice took decades to become routine. The summary below follows the history in the FAO's overview of embryo transfer in cattle.

From Laboratory Idea to First Calf

The first embryo transfer in cattle was reported in 1949, and the first calf born from the technique arrived in 1951. For the next two decades it stayed mostly a research tool.

The core steps that later became standard are superovulation, which stimulates a donor to produce multiple eggs, recovery of the embryos, transfer into recipients, and cryopreservation, which allows embryos to be frozen and stored.

The 1970s Boom and the 1977 Crash

Commercial interest took off in the early 1970s, when European dual-purpose breeds became popular in North America, Australia and New Zealand. Breeders wanted to avoid the high costs and long quarantine periods of importing European stock, and they hoped to profit from rare progeny.

Demand for embryo transfer services arrived before veterinarians and reproductive physiologists could fully meet it. Clinics sold the technology to the public, and techniques advanced quickly. Then in 1977 the North American market for these breeds collapsed. The value of the offspring had depended on scarcity, and the rising number of animals produced by the technology itself pushed prices down.

Why Breeders Use It

For a seedstock breeder, embryo transfer multiplies the influence of the best females. Tools such as expected progeny differences, explained in the Drovers guide to EPDs, help breeders compare animals on the traits they want, and embryo transfer gives them a way to act on what the numbers show.

Breeders had wanted embryo transfer in part to avoid the high costs and long quarantine periods of importing European stock, which is why interest ran so high when those breeds were fashionable.

Costs and Limits

The 1977 collapse is the best-documented limit. A technology that makes rare animals common cannot keep prices at rare-animal levels, because the value of the offspring depended on scarcity.

The excerpt used here does not discuss biological limits, and it gives no statistics on how many calves the technique produces, so this page leaves those out.

Learn More

Read the full history at the FAO document on embryo transfer in cattle and the FAO chapter on commercial development. For related ranch and breeding stories, see the ranching section of farm.FM or a farm.FM story about breeding cattle.