Utilization of Embryo Transfer in Beef Cattle
John F. Grimes
Agriculture and Natural Resources, Highland County
Today's beef cow-calf producer has access to more tools than ever to make genetic progress within his herd. Technological advances in heat synchronization, data collection through the use of electronic I.D., and ultrasound measurements to determine carcass merit are a few of the tools being used more frequently to improve the genetic makeup of our breeding herds. Embryo transfer (ET) is being considered by more breeders as a means to make genetic improvement.
ET is not a new technology. It's earliest roots trace back to work done with rabbits in 1890. Sheep and goats were successfully propagated in the 1930s and it was not until the early 1950s that live beef calves were generated from ET. It was not until the early 1970s that the first commercial ETs were accomplished in the United States. These early transfers were completed using surgical techniques. The adoption of non-surgical transfer techniques signaled an increase in the use of ET.
Purpose of Embryo Transfer
The use of ET in the beef industry has been implemented by purebred breeders with some minimal use by club calf breeders. The breeders who have utilized ET have been pursuing these basic goals: to improve genetic selection by increasing the number of progeny from females that are either proven or perceived to be superior under any number of criteria; or to multiply the number of cattle in a program in order to expand the herd or to meet market demands.
There have been additional reasons given to rationalize the use of ET. Supply and demand will always result in semen with increased value. ET will allow a breeder to generate more offspring from rare and valuable semen.
It has also been stated that ET will increase the accuracy of selection traits. Caution should be used before putting too much faith in this argument. Even with the...