According to the weight of the donor sheep, 215-510 ml of rapid sleep anesthesia was injected into the neck muscles. After 20 minutes of injection, the anesthetized donor sheep was tied to the surgical frame on their back, shaved, and the surface of the skin to be operated on was washed with soap and water. Then, iodine and alcohol cotton balls were used for disinfection. The surgical incision was made about 6 cm on both sides of the midline near the breast, and a self-made EVO live egg collection instrument imported from the United States was used

The device consists of five parts: an egg collection needle, an egg collection catheter, an egg collection tube, and Du's PBS solution containing heparin anticoagulant, a flow control valve, and a suction device. Before egg collection, the flow rate of the suction device is first adjusted (about 0.15 ml/s), and the EVO needle of the live egg collection instrument is directly inserted into the visible follicular cavity to extract the oocyte cumulus cell complex from the follicle. Transfer the collected oocyte collection solution containing oocytes into a collection cup with a filter on the wall, and then rinse it with three times the volume of fresh oocyte collection solution. After standing still for a few minutes, detect the oocytes under a physical microscope. Wash the oocytes three times with oocyte culture medium, transfer them to a balanced oocyte maturation culture medium covered with mineral oil in a four well culture plate, and culture them in a CO2 incubator (381 ° C, 5% CO2, 95% air) for about 27 hours. Observe the maturation of oocytes intermittently. The typical radiative diffusion of cumulus cells and the expulsion of the first polar body from oocytes under inverted microscopy are used as criteria to determine the maturation of oocytes. Mature oocytes were washed with 300 IU/ml hyaluronidase solution to remove loose granulosa cells (retaining dense 2-3 layers of granulosa cells). Then use Boer goat live egg collection and oocyte in vitro fertilization technology to wash the oocyte cleaning solution three times, and wait for in vitro fertilization treatment.

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