Rules for taking semen from a bull and how to assess the quality of semen, storage conditions
Livestock complexes produce artificial sampling of bull semen to restore and increase offspring. This approach makes it possible to obtain high-quality offspring, and the ejaculate of one donor is enough for the fertilization of several females. With the correct technology of freezing, semen can be stored from 1 day to several years.
Pros and cons of artificial seed collection
Cattle breeders increasingly collect sperm on their own, arguing that artificial insemination of cattle has a number of advantages.
Advantages of the procedure:
- one portion of semen is enough for insemination of several females;
- the herd population is constantly renewed, while there is no need to purchase new breeding bulls;
- for artificial insemination, pure sperm is used, which will not become a source of spread of sexual infection;
- ejaculate is collected only from the best donors, which significantly improves the breeding composition of the herd;
- Thanks to the semen can, you can plan an organized simultaneous offspring. So it is much more convenient to care for young animals.
There are drawbacks to this method of semen sampling, but they are insignificant: you need to equip the room, in the process you need the help of a qualified specialist.
How to collect semen from bulls
Before proceeding with the preparation of the ejaculate, special procedures are carried out in relation to the bull. Knowing the character of the donor, the breeder chooses the method of bringing him to the pen. The fence is carried out only after preparatory manipulations.
Animal preparation
The donor takes a shower immediately before the procedure. It is cleaned, washed with baby soap and warm water, the temperature of which should be within + 18 ... 20 ˚С. Semen collection is carried out no earlier than an hour after the last meal.
So that the sexual reflex wakes up in the bulls, and the ejaculate collection passes without problems, they are led in a series in a circle.
At the same time, make sure that the manufacturer walking behind does not touch the skin of another animal with the penis. Having brought the bull to maximum erection, it is led into a machine, previously irradiated with fluorescent lamps.
Process directly
A dummy animal or a mannequin is used for cage. Algorithm of actions:
- The zootechnician puts on gloves, after which he is given an artificial vaginal organ, which must be installed at an angle of 30-35 ˚.
- When the donor climbs onto the penis, the penis is grasped by the foreskin and gently inserted into the funnel of the vagina.
- After the push, the semen erupts, the artificial organ is removed, it is sent to the laboratory.
Between visits on the fence of the testis of the bull, they walk for 15-20 minutes. To prevent the donor from developing an inhibitory reflex, it is necessary to change the place of the procedure and the dummy.
How to evaluate quality?
The resulting ejaculate is examined for the presence of live sperm. The best option is 1 billion units in 1 ml, while at least 90% of them perform rectilinear translational movements.
Volume
The nominal normal semen volume is 4-5 ml. If at a time the bull gives a smaller amount of seed, it is necessary to revise its diet, conditions of detention, and not write off everything on the violation of reflexes during ejaculation.
Colour
Research is carried out in a well-lit room. Good quality semen should be white with a yellow tint. If the semen is pink or red interspersed, blood has entered the ejaculate. A yellow tint indicates that urine has penetrated, green indicates purulent discharge.
Consistency
The seed of normal consistency is homogeneous, and resembles cream in density. If there are impurities or flakes in the semen, the semen is of poor quality.
Smell
When the liquid “smells like” a putrid aroma, it means that disease-causing processes take place in the genitals. The ejaculate of a healthy animal is practically odorless. In some cases, semen may smell like freshly milked milk, this is normal.
How to store seed material?
After collecting sperm, it is preserved by reducing the metabolic processes of sperm. This allows you to increase the shelf life of the ejaculate for fertilization.
Short term
For short-term storage of biomaterials, yolk diluents are used, which increase the resistance of spermatozoa to temperature shock. Components of the semen preservation product:
| Nutrient | amount |
| Medical anhydrous glucose, g | 30 |
| Purified water, ml | 1000 |
| Chicken egg yolk, ml | 200 |
| Sodium citrate, g | 14 |
During storage of the ejaculate, changes in temperature should be insignificant. Therefore, the seed is placed in a thermos or a special refrigerator. Diluted semen is packed into small vials (ampoules, test tubes), filling them to the very top. This is necessary so that the ejaculate does not loosen during transportation.
A container with semen is packed in foam rubber or wrapped with cotton wool, placed in a plastic bag, which is tightly closed. After that, it is cooled to a temperature of 2 ... 4 ˚С.
Seed material preserved by this method is used within 24 hours. After this period of time, the fertilizing ability of the sperm drops sharply.
Long-term storage
Nowadays, they often resort to low-temperature freezing of the ejaculate, in which it is possible to store it for a long time in liquid nitrogen. This method allows you to save the fertilizing ability of sperm for several months (years). Another plus is that you can create a large supply of biomaterial.
With the nitrogen freezing method, compliance with the strict regime is mandatory. Temperature fluctuations above -150 ˚С are unacceptable. Ampoules or granules with sperm products are placed in stationary containers located in special storage facilities.
