An often-overlooked component in the process of creating pregnancies on a dairy is semen tank management. When maintained properly, the semen tank will preserve the viability of the genetics within. Like many things on a well-operated dairy, when protocols are followed, positive results will occur. When ideal measures are taken and technicians are well trained, the highest possible conception rates will be achieved. There is a significant monetary, genetic and reproductive investment in storage and handling of semen. Most potential issues can be avoided with proper education. Tank care, use and maintenance, like proper semen handling, is an area in which technicians and farm management can fully control execution.
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.
Establish an organizational system
A well-organized tank will ensure semen is handled properly. Simple tank etiquette will help all users work in an efficient manner. When a new cane is used, the cane top should be bent up at a 45-degree angle to allow clear access to the straws; this also signifies an open cane. There should not be multiple open canes for the same sire. All semen from the top goblet should be used before starting a bottom goblet. This will allow the technician to quickly find the open cane when more than one cane of the same sire is present. When canes of the same sire are used one at a time, tanks will have more space to add additional inventory.
Even when technicians are careful retrieving semen, straws, goblets and canes may fall to the bottom of the tank. Do not stress if you find yourself in this position. If you take the wrong approach in retrieving lost items, you may risk damage to the semen in the tank. The last thing you want to do is impact future conception rates. When this happens, you will need to decide if it is something you need to fix immediately. If the tank can be closed properly, continue with the breeding that needs completed. If it is a straw or goblet, it will likely not impact the use of the tank. When a cane gets to the bottom, it can get in the way of putting canisters in place. To remove a cane, it is best to work with your supplier to remove it.
Maintaining a current semen inventory will also reduce time spent looking for semen and mating cows. Most dairy management software features a running semen inventory report. A hard copy can also be printed and used each day. When using management software, accurate sire codes are key. Labeling canisters on the tank or using a dry erase board with canister-by-canister sire location will reduce time locating sires. Accurate inventory will help producers make purchasing decisions that are in line with their genetic goals for the herd. Modern genetic strategy calculators will provide producers with projected semen usage for sexed, conventional and beef semen, so producers can purchase according to their needs. When producers continue to store sires that no longer meet the herd’s genetic expectations, it limits the herd’s genetic potential. Finish older inventory before starting new groups of sires. Inform A.I. personnel of changes in breeding strategies and matings to ensure genetic goals are achieved.
Dairy producers face many challenges. Animal health, nutrition, milk markets and personnel management cause many farmers to lose sleep. Maintenance and management of a semen tank is a factor that every dairy producer can control. It should never limit the reproductive success and genetic potential of any operation. Be diligent in maintaining proper practices and you will reap the rewards.
Keys to semen tank success
- Elevate tanks off bare concrete in a ventilated, well-lit, dry, safe place.
- Be aware of any tank frost from liquid nitrogen loss due to tank failure.
- Routinely measure nitrogen levels and notify your supplier of rapid liquid nitrogen loss.
- Use one cane at a time to avoid multiple open canes of the same sire.
- Keep an up-to-date inventory and sire location for quick semen handling.
- Use old sires prior to using new sires and keep all personnel up to date with genetic strategies to avoid excess inventory.
