Surgical removal of the main reproductive organs of domestic animals. Chinese veterinarians call it castration. The purpose is to eliminate the sexual desire and reproductive ability of livestock, so that the temperament of livestock becomes docile and hard-working and easy to manage; The meat quality of meat animals is improved and the yield is increased; It can also control the mating behavior in the herd, which is beneficial to the reproduction and breeding of improved varieties. Male castration, also known as orchiectomy; Female castration, also known as ovariectomy, is called "flower picking" in China. In addition, there are male drug castration and bloodless castration of testis. Generally, the scrotal skin is cut with a knife, and then the testis and its attached tissues are broken by different methods to squeeze out the testis. Among them, the fire-bending method is to clamp the spermatic cord with a small splint at the upper end of the testis near the groin, and then burn the spermatic cord and blood vessels with a red-hot iron. This method is ancient and popular in the pre-Qin period. Its advantages are complete hemostasis, but its disadvantages are slow wound healing and easy infection and suppuration at the burn. The water-pressing method was founded in the Han Dynasty. After the scrotum was flushed with cold water and the testis was squeezed out, the spermatic cord was separated from the blood vessels, and the spermatic cord was cut off with a knife. The blood vessels were picked and scraped with thumb and food fingers until they were torn and broken. This method can heal wounds quickly, but sometimes it can't stop bleeding completely. Ligation method uses surgical suture to tie the arteriovenous blood vessels above the testis, then cuts off the spermatic cord and blood vessels with a knife and takes off the testis. At present, this method is mostly used for castration of horses, cows, boars, dogs and cats.

In ancient times, when the cow was castrated, it was made to stand in a standing position, which was called standing. Walking is that the assistant leads the cow by holding the cow nose rope in front, and the performer stands behind the cow to castrate the cow. The operation is skilled and fast, and the two testicles are removed in a short time when the cow feels pain and resists forward. The "picture of refusing dragons and castrating cows" unearthed in the Han tomb is a schematic diagram of walking.

The so-called bloodless castration method, that is, instead of making an incision on the scrotum, uses a steel castration forceps or a clamp such as a clamp or splint or a string to forcibly tighten the spermatic cord at the base of the scrotum, so as to block the blood flow and make the testis atrophy without nutrition. The spermatic cord of cattle and sheep is long, so this method is applicable; For sheep, you can even tighten the base of scrotum directly with rubber bands for castration. The cock's testicles are located under the lumbar spine in the abdominal cavity. When castrating, it is necessary to cut the abdominal wall, pierce the membrane and air sac with a testicle spoon, tighten the testicles with a simple testicular device, and then take them out of the body with a testicle spoon. Now there are also implants or injections of estrogen preparations for castration, but after the drug effect, they return to males. Chicken castrated by this method contains excessive estrogen and is not suitable for consumption. Hens are generally not castrated, but a few places in Yunnan Province, China have the habit of removing hens' ovaries to improve their meat quality.