As the last calves are born and breeding season approaches, many producers are ordering CIDRs and synchronization drugs, calculating postpartum intervals, and carefully observing for signs that the cow herd is ready to be bred again.

What many cattlemen fail to think about, however, is that dusty semen tank sitting in the back corner of the barn. It is natural to lose sight of something we use for only a short time, but we cannot forget that the bull is half of the equation in producing calves!

Given the amount of time spent executing an estrous synchronization and artificial insemination protocol, it is imperative that semen handling is not overlooked. This article will include tips on handling semen before and during the breeding season.

In the off-season

Only purchase semen from proven companies in quantities that will be used within 6 months.

Although newer tanks can hold liquid nitrogen up to eight months, levels should be monitored regularly. Temperatures below -320 F can be maintained with as little as two inches of liquid nitrogen, but keeping levels above the cane tops when canisters are secured is recommended for optimum storage. Your semen distributer can deliver nitrogen on-farm or direct you to a supplier.

A semen tank is made up of two chambers. The inner chamber is suspended from the outer shell by the neck tube. Due to this, any additional stress on the neck should be avoided and one should always carry and secure the tank properly in transit.

Low temperatures are able to be maintained in the inner chamber due to a tight vacuum and solid insulation between the two chambers, so any loss in vacuum leads to an increase in temperature and quick evaporation of liquid nitrogen.

Store the semen tank where it can be seen daily, in a cool place out of direct sunlight. Watch for frost or sweat on the tank, an indicator that the tank has failed.

Shield the tank from corrosion by keeping it elevated above concrete or dirt floors that can become wet or muddy.

Maintain an accurate tank inventory sheet detailing the location of semen from individual bulls to prevent unnecessary searching. Use a separate canister for each bull when possible.

If more than one semen tank is in use at a ranch, pool all of the semen needed on a particular breeding day in a single tank to avoid needless exposure of other stored semen. Transfer between tanks should be well organized and conducted quickly with tanks side-by-side and two people to move canes between tanks.

On breeding day

Plan ahead. Assign jobs to individuals and decide which bull each cow will be bred to before she gets in the chute.

When removing semen from the tank, first use an inventory sheet to identify which canister contains the desired semen. Detach the canister from its resting position, move it to the middle of the tank, and raise the canister no higher than two inches below the top of the tank. Immediately after the appropriate cane is located, lower the canister to the bottom of the tank. Keep the cane as low in the tank as possible and remove the desired straw, placing it directly in a warm water thaw.

Locating a straw should take no longer than 10 seconds. If the straw cannot be located quickly, lower the cane back into the tank until the liquid nitrogen stops boiling and try again.

Semen should be thawed in a warm water bath at 95 掳F for at least 40 seconds. Use a thermometer to check the water temperature. Just because the green ready light is lit, does not necessarily mean the water is at the optimum temperature! Also, only thaw the amount of semen that can be used in 5 to 10 minutes.

Warm the insemination gun with a clean paper towel and keep it next to your body to avoid cold shock of the semen. Once semen is thawed, dry it quickly and thoroughly with a paper towel. Shake the straw while holding the crimped end to avoid any semen loss while cutting.

Transfer the straw to the warmed AI gun and cut the straw squarely. Assure the straw has formed a firm seal with the sheath and tuck the gun inside clothing until use. The time between removal of a straw from the semen tank to the cow should be less than 15 minutes.

Lastly, keep in mind that sunlight, water, and cold shock kill semen quickly. If the above precautions are taken, this should allow one to deliver enough viable, fertile sperm to allow for fertilization.