What techniques and methods are there for artificial insemination of cattle?

At present, cattle artificial insemination technology is already very widespread in our country, and it has played a very important role in the improvement of yellow cattle and dairy cattle in our country, with the coverage rate of improved breeds continuously rising.So what techniques and methods are there for artificial insemination of cattle?

Natural mating of cattle is inefficient and requires too many breeding bulls. Nowadays, artificial insemination is generally adopted. Recently, a reporter interviewed Professor Lin Qing, a member of this newspaper's expert advisory group and of the College of Animal Science and Technology at Northwest A&F University, on the question of cattle artificial insemination techniques.

1. Selection of breeding bulls

Each cattle farm roughly needs only a few breeding bulls. Breeding bulls are generally selected for good breed and gentle temperament, and they must be guaranteed to be replaced regularly. The raising of breeding bulls must be very refined; when feeding concentrated feed and forage, a certain proportion of eggs, fruit and sugar must be included. In addition, breeding bulls must frequently undergo physical examinations to ensure they are healthy and sturdy.

2. Artificial semen collection

For semen collection, the collection tube must first be cleaned thoroughly, using physiological saline, distilled water and 75% alcohol. The rubber sleeve is fitted smoothly onto the collection tube and washed more than 3 times. During collection, the collection tube is heated to about 38°C, the estrous cow is fixed in the stall, and when the bull is led to mount, the collector holds the semen collection device by hand to collect the semen; during collection, attention must be paid to the personal safety of the operator. After collection is completed, its activity is observed under a microscope; once it is confirmed that sperm activity is good, it can be diluted with distilled water, loaded into tubes and sealed for storage.

3. Artificial insemination

The sealed fine tube of frozen semen is placed in 40°C warm water to thaw, then checked under a microscope; if the check shows no problem, insemination can proceed. A gloved hand is formed into a cone shape and, with the lubricating effect of paraffin oil, inserted into the rectum of the estrous cow to help the cow expel retained feces; the hand is then inserted deeper into the rectum to feel the uterine horn, check the condition of the ovaries and uterus, and grasp the cervix along the way. The hand holding the cervix slides gently to stimulate the cow's sexual excitement. A healthy cow in peak estrus will have egg-white-like mucus flowing out from the vagina; based on the properties of the mucus, it is possible to determine whether there is uterine disease and the state of estrus. At this point, professional tools such as an insemination gun are needed, and the insemination procedure must be carried out by professional personnel.