Nitrogen tanks are essential equipment for the application of the artificial insemination (AI) technique, since they allow the conservation and storage of frozen semen, for prolonged periods. This facilitates the use of AI in many livestock farms worldwide. With the AI technique, we can obtain semen from the male reproductive tract, breed and preserve it, and then introduce it into the female genital tract, using special instruments.
Semen is a biological product that must be kept at temperatures of -196°C, to ensure the vitality of the sperm during transport and storage. To achieve this temperature, tanks of liquid nitrogen are used. These are cryogenic thermos whose double wall designs favor the maintenance of the cold provided by liquid nitrogen (LN2) inside the tank. The temperatures achieved with this system, allow the conservation of semen for extended periods.
This provides advantages to different livestock systems, such as facilitating the national and international transport of semen, avoiding the transfer of breeding males. Reduced health risk, through prevention and control of diseases, as direct contact between male and female is avoided. All this promotes the reduction of costs and generates a positive impact on the management of livestock worldwide.
Basic structure of a liquid nitrogen tank
It consists of two containers, one inside the other, between which there is an empty space. The outer part must withstand the environmental thermal oscillations; the inner part contains nitrogen; it is emptied and has no welds, which favors a uniform temperature. Its special alloy allows to withstand extreme temperatures. This inner container, connects to the outer wall through the neck. This point is critical and fragile, so a sudden movement or blow can cause a thermal fracture.
The tank has a cap made of insulating materials, to prevent liquid nitrogen from evaporating quickly. However, it must favor an escape route, to reduce the pressure inside the thermos and not increase it dangerously.
The lid has a design with grooves that accommodate the arms of the containers where the semen straws are housed. These have a cylinder whose size varies depending on the thermos and the size of your neck. The containers are attached to the neck of the thermos.
Aspects to consider for the care of the nitrogen tank for artificial insemination
The tank represents an important investment within the equipment used for AI, so it must be handled carefully, avoiding shocks and kept in protected places, protected from direct sunlight. The area where the tank is located should be clean, dry and well ventilated, but without strong wind currents. The tank should be separated from the floor, preferably on a wooden platform, without contact with dust or corrosive materials and compounds.
It is also important that the tank location facilitates its filling with liquid nitrogen. In addition, this site should have lighting that allows frequent monitoring of nitrogen level. To minimize the movement or transport of the tank, in order to avoid shocks that may damage them. When it is necessary to move it from one place to another, it should be lifted by both handles and preferably by two people. If you are going to be transported in a vehicle, secure it with ropes or tapes that prevent movement.
It is advisable to confirm the semen inventory before removing it from the tank, to ensure that the correct basket is being handled. In addition, it is preferable to keep the same bull or bulls of the same breed, in a single basket.
Uncover the tank when strictly necessary, as every time the tank is uncovered, it loses nitrogen. Do this only in the following cases:
- To pull out the straw he’s going to inseminate with.
- At the time the nitrogen is to be measured.
- When nitrogen is applied.
- When semen inventory is taken.
Criteria for the selection of a nitrogen tank
There are different types and sizes of tanks; they can be classified as follows:
- Work tanks.
- Transport tanks.
- Tanks for storage.
In the first line there are those used for AI tasks in the field. In the second, there are those that are used for the transport of frozen semen or nitrogen, while in the third there are those that are used in semen banks.
The selection will be made depending on the specific needs of each livestock company. It is advisable to take into account the number of animals to be inseminated, the length of the service season, the amount of semen to be stored, the availability of nitrogen in the area and the economic possibilities of the producer. Perhaps the most appropriate approach is to use the cost of storing doses of semen per year, which is more appropriate for the livestock company.
Kalstein Nitrogen Tanks
A wide range of Nitrogen tanks of the YR series is offered, in which you can choose the most appropriate for the purpose of the livestock company. These products offer high thermal efficiency, extremely low LN2 evaporation loss storage and advanced vacuum and super insulation technologies.