Embryo Transfer

Embryo transfer is the process of taking fertilized embryos from one animal and inserting them into another. This is very useful today in cattle, because now it is economically feasible and it allows the producer a greater number of offspring from one cow with desirable traits. The process starts normally by artificially inseminating the cow. Exactly seven days later, the uterus is flushed, and the embryos and ova. Next, the embryos will be isolated. The embryos are then inserted into the recipient cow.

Artificially inseminating the cow is the preferred way to fertilize the eggs in the donor cow. The cow should be inseminated at least three times at intervals of twelve hours, to insure fertilization. In preparation for AI, a shot of FSH (Follicle Stimulating Hormone) should be given to the cow to super-ovulate her. This causes more eggs to drop from the ovaries, allowing more embryos. Seven days after the cow is inseminated the third time, her uterus should be flushed.

Before flushing the cow, her posterior should be cleaned up as much as possible. After this is complete, an instrument known as the "introducer" is inserted into the vagina. The instrument is much like a long syringe with a plunger going through the center. The vet then will push his hand through the anus and guide the introducer along the cervix. The instrument is pushed through the cervix and into the uterus. Once it reaches the uterus, the plunger is pulled out and a catheter is inserted into the uterus, against the uterine horn, through the center of the introducer. The "cuff," a small balloon type object, is inflated in the cow's uterus, and a sodium based phosphate is released for lubrication. It is then pumped back through the introducer, and filtered by an embryo filter. The liquid caught by the filter is then examined to determine the number of good embryos. At this stage, the sex can even be determined. They are graded, then placed in straws or frozen for later use.

Implanting the embryos into the cow is done just like