Using embryo transfer technology is another tool in the toolbox for cattle producers looking to improve genetics.
It’s used in some segments of the industry more than others, says Patrick Wall, Extension beef specialist with Iowa State University based in southern Iowa.
“You see it used by purebred breeders and those in the club calf business,” he says. “Most associate embryo transfer technology with the dairy industry, but it’s not used as much there as you might think.”
Two options are available, Wall says. There is an embryo flush, where all embryos are collected at once. That’s a more traditional option, he says.
In vitro fertilization (IVF) is another option, and Wall says that can be done on an open or pregnant cow.
“It’s better if you do it on a pregnant cow for better hormone levels,” he says. “You’re just harvesting the oocytes, and you can fertilize those with sexed semen to get more of the sex you are wanting.”
Wall says a conventional flush could cause a cow to stop creating embryos. He says IVF is less likely to cause that problem.
With IVF, Wall says the result could be 1 to 18 fertilized eggs, which allows a producer to stretch out the use of semen.
“The concern a lot of the time is cost,” he says. “Sometimes you are using semen from a deceased bull, and that can get expensive.”
Selecting the right donor and recipient cows is important, says Alex Snider, a research physiologist with USDA’s U.S. Meat Animal Research Center in Clay Center, Nebraska.
People are also reading…
“You want to make sure you have those selected cows lined up before you get started,” she says. “Make sure the cows are reproductively sound, have a good mothering ability and are able to wean a calf.”
Snider says the numbers of recipient cows will vary depending on number of embryos, but it’s good to have at least 10 to 20 ready to go.
She says a donor cow you select for an embryo collection protocol should generate an average of 10 good embryos, but that could vary depending on multiple factors, such as
diet during the super-ovulation protocol, environment or the selected female herself.
She says embryos should be transferred roughly one week after a cow comes into heat.
“Your timing window is very small for transferring embryos,” Snider says.
The average success rate for embryo transfers is in the 40 to 50% range. She says much depends on the ability of the technician, adding the success rate is similar to what is found with artificial insemination.
“If you have a good management system in place, you should be pretty successful,” Snider says.
Wall says while more and more producers are interested in embryo transfer technology, use has held fairly steady.
“There’s a small segment of the industry that uses it,” he says. “The usage is somewhat tied to grain markets because you need cash to do it. If a grain farmer does pretty well, this is something they might be interested in trying.
“If you want to try it, do your homework first. Remember to start slowly — you need to crawl before you can walk.”