What Is Donor Insemination?

Washing eggs. After the eggs of some fish are laid, they can only hatch after undergoing the washing process. The flushing of eggs is generally to use various methods to make the water around the eggs flow so that oxygen can meet the requirements of egg hatching. The eggs of the four major fish require a strong water flow, while clownfish and other fish just flush the eggs through constant incitement by their parents. Washing the eggs is to flush the embryos from the uterus into the buffer and temporarily place them in order to observe the development. At the same time, the embryos are ready to be transplanted into the recipient's uterus on the seventh day after mating or insemination. The egg device flushes the embryos from the donor's uterus.

Flush eggs

The first method is to collect oocytes from experimental animals such as mice, rabbits, and small domestic animals such as pigs, sheep, etc., which can be treated with gonadotropins to make them release more eggs, and then washed from the fallopian tubes at an appropriate time. Fertilize the egg and allow it to fertilize in vitro directly with the capable sperm.

The second method is to remove the ovary from a female animal that has just been slaughtered, and then collect oocytes from the ovary.

Oocytes can also be collected directly from the ovaries of live animals, called live egg collection. An ultrasound probe, an endoscope, or a laparoscope is needed to draw oocytes directly from the live animal's ovary.

The latter two methods are applicable to domestic animals and large animals. The collected oocytes need to be matured in vitro before they can fertilize with the capable sperm.

Superovulation: Also referred to as "superovulation", it means that the donor cow is treated with hormones to make it estrus and can discharge a large number of mature eggs. After reasonable artificial insemination methods, a larger number can be obtained Transplantable embryo.

Thinking and Exploring

1. The picture on the right is a schematic diagram of the technical process of embryo breeding for breeding dairy cows after the students visited a breeding farm. Look at the diagram to think and discuss the following questions.

(1) Complete the following flowchart with text.

Answer: Select the donor and recipient females, and perform estrus treatment at the same time; breed or artificial insemination; collect embryos; embryo transfer;

(2) How should donor males, cows and recipient cows be selected? In step , why do we treat donor cows with gonadotropins, and why do we need to perform simultaneous estrus treatments on donor and recipient cows before treating them with gonadotropins?

Answer: Donor cows and cows should be individuals with excellent genetic traits required by humans, and recipient cows must have the ability to normally breed and reproduce offspring; donor cows need to be treated with gonadotrophins to cause Super ovulation, so that more embryos can be obtained; before gonadotropin treatment of donor cows, the donor and recipient cows are subjected to simultaneous estrus treatment, so that their physiological conditions can be synchronized or consistent, so that Somatic embryos have the same or similar survival conditions after being transferred into the recipient.

(3) In the flow chart on the right, which step requires egg flushing? Is flushing the eggs of the female?

Answer: Step requires egg flushing, which refers to flushing out the fertilized eggs in the donor mother animal instead of flushing the eggs.

Method for collecting eggs from washed eggs

Washing eggs (5 photos)

For mating or insemination donor embryos, embryos are collected over time. The specific operation method is to flush the embryo located in the uterus or fallopian tube with the prepared egg flushing liquid and a special egg flushing device, which is also called flushing eggs. After that, the embryo is checked for quality. The time for flushing the embryo is generally 3 to 8 days after mating or fertilization, and the embryo has developed to more than 4 to 8 cells at this time.

There are two methods for flushing eggs: surgical methods and non-surgical methods. In the early days of embryo transfer technology, surgical methods were used to flush eggs. At present, non-surgical methods are mostly used for cattle, horses and other domestic animals, while small domestic animals or experimental animals are still used. Surgery. The surgical method of flushing the eggs requires incision in the appropriate part of the abdomen according to the requirements of surgery, and quickly finds the fallopian tube and uterus and leads out of the body. Generally use a syringe to aspirate egg flushing liquid, inject the egg flushing liquid from the abdominal cavity opening or uterine horn of the fallopian tube, and insert a plastic tube from the corresponding other end (uterine horn or fallopian tube) to extract the egg flushing liquid containing the embryo. Rinse separately. The exact location of the eggs should be determined according to the type of livestock, the time of mating, the speed of embryo growth and the location of the embryo. The amount of flushing liquid should be based on the volume of the uterine horn. The egg flushing operation should strive to be rapid and accurate to prevent damage and adhesion to the reproductive organs.

Non-surgical egg flushing can be used on cattle, horses and other domestic animals. Generally, egg flushing is performed on a special egg flushing tube on the seventh day after mating. The flushing tube is first introduced into an appropriate position in the uterine horn. With the balloon outside the flushing tube, the position of the flushing tube is fixed and the flushing site is closed to prevent the flushing liquid from flowing into the reproductive tract. When rinsing, first inject the flushing liquid into the closed part of the uterine horn, and then discharge after rinsing, and repeat. ^[1]

Take cattle as an example, as shown in Figure A and B:

Take cattle as an example, as shown in Figure A and B.