Breeding Matters - Frozen Assets: protecting every step of the genetics journey
Date Posted: 24th June 2026
From storage to conception, on-farm artificial insemination demands precision and best practice. Bovine semen straws, and more particularly the fragile sperm cells they contain, are incredibly vulnerable, and must be protected from thermal shock, cold/heat stress and contamination.
Good management, thorough maintenance, and correct handling maximise conception rates, avoids wasted genetic investment and ensures a profitable calving season.
And with the average cost of a calving index exceeding 365 days estimated at between £2 and £9 per cow/per day, the best way to avoid a ‘penny-wise, pound foolish’ outcome is to adopt a ‘safe as houses’ approach.
I recommend following three clear steps:
Tank Environment: It all starts with the tank. Semen is stored using the cryopreservation method where the straws are held in insulated flasks holding liquid nitrogen at a constant minus196°C The tank should be elevated at all times – ideally on a wooden pallet - as contact with a concrete floor can cause alloys within the concrete to interact with the flask, leading to erosion.
It is also important that the tank is stored in safe areas where there is minimal risk of impact from other machinery or animals. Any bangs or knocks could compromise the vacuum within the flask or cause liquid nitrogen to leak, resulting in straw damage.
Liquid Nitrogen Management: Checking and controlling liquid nitrogen levels is vital and should be done on a routine basis. During busy period of AI I recommend the tank is dipped on a weekly basis. The liquid nitrogen level shouldn’t fall below 4cm but if it does, the tank should be topped up asap. Older tanks may require more regular top ups and I would advise servicing to address any issues.
Semen Handling: It’s important that the frozen semen straws are not over handled or exposed to temperature fluctuations. Raising a straw above the ‘frost line’ in the neck of the tank (even briefly) can damage sperm mobility. Inventory logs which map each straw’s exact location are crucial to ensure they are not over handled or spend excess time above the minus 196°C threshold. Keeping records completely up to date is also vital.
Do not use fingers to locate a straw as any level of touch by human hand can lead to ice crystallisation within the cells, potentially impacting on conception. Instead use pre-cooled tweezers and try to locate the straw within five seconds. Once selected, use a proper thawing bath, with water which is 35-37°C to transition the sperm from its frozen to active state.
I always say, if it’s worth having, it’s worth protecting. Following these protocols could prevent avoidable conception failures and guarantee best outcomes for dairy and beef farmers. If in doubt the Ai Services team provides a range of specialist services, from tank and semen viability testing to DIY training and liquid nitrogen delivery. The end goal is to make sure your AI processes and systems are running at an optimal level, delivering the best financial outcomes for the farm.
