Storage environment
The most basic component of tank care is the storage environment. In my nearly 20 years in the A.I. industry, I have seen some less-than-ideal environments for semen tanks. Areas with large swings in temperature and exposure to excess moisture can wreak havoc on the longevity of a tank’s service life. Excess moisture can cause corrosion to the tank and, in turn, result in the tank losing its insulating vacuum. Semen tanks should not be sitting directly on concrete. They should be placed on wood, foamboard or a rubber mat. Semen tanks should also be stored in a safe, well-lit, ventilated location that will reduce any risk to the user or the tank.
I suggest creating a workstation that is built for proper semen handling that avoids the path of cattle and equipment. Any damage to the tank can lead to the loss of the tank’s ability to maintain a proper temperature. The neck plug also needs to be properly sealed. If frost is noticeable on the top of the plug, the plug should be replaced. If frost is present on the outside of the tank, it is an indicator that there is liquid nitrogen escaping and is a sign of tank failure. Excess liquid nitrogen loss shortens the maximum hold time between nitrogen fills. If you suspect tank failure, you should contact your liquid nitrogen supplier immediately.
Monitor liquid nitrogen levels
The service life of a semen tank can end quickly, and all personnel need to be aware of the warning signs. It is the responsibility of the liquid nitrogen service person and the farm staff to keep an eye on liquid nitrogen levels. Liquid nitrogen levels can be monitored using a yardstick. Most A.I. suppliers carry these in their trucks. Ideally, the maximum service interval is eight weeks. During this time, liquid nitrogen may be reduced to 8 to 10 inches.
Expected hold times and volume depend on the model of a semen tank. When purchasing a new tank, manufacturer specs will list the expected maximum weeks the tank will hold between fills. If you are suspicious there’s not enough liquid nitrogen and the tank is down to nearly 2 inches, you should reach out to your service person immediately. If it is less than 2 inches or dry, you should stop using the semen until semen viability can be verified to avoid fertility issues.
Written for Progressive Dairy, appeared in their May 7, 2025 issue.