Proper Semen Handling Techniques
Dairy Pipeline: December 1997
Ray L. Nebel
Extension Dairy Scientist, Reproduction
Lets review proper semen handling techniques. It is essential that frozen semen be handled and thawed carefully and properly to maintain sperm viability to obtain optimal conception rates. Insemination equipment should always be kept clean, dry, and warm. Time and temperature are the two critical factors in proper thawing of frozen semen. A thermometer should be used to obtain the proper water temperature of 90 to 95 degrees F. The thermometer should be calibrated with a reference mercury thermometer every 6 months. A semen inventory for each canister in the liquid nitrogen tank will prevent searching and may expose semen to temperatures in the neck tube which can alter the ice crystals and cause cell damage. When removing the straw from the nitrogen tank, the handler should gently shake the straw to remove any liquid nitrogen that may be retained in the cotton plug end of the straw. The thaw should be timed with a watch to avoid guessing. Thawing time should be 45 seconds minimum. While the semen is thawing, the handler warms the insemination rod by rubbing it briskly with a paper towel. Once warmed, the handler places the insemination rod within his or her clothing so that it will be close to the body to maintain warmth. After the semen is thawed, the straw is dried thoroughly with a paper towel and protected from rapid cooling. The air space in the straw should be adjusted to ensure that no semen will be lost when the end of the straw is cut off. This can be done by slightly flicking the wrist while holding the straw at the crimp-sealed end. Only sharp scissors or a specially designed straw cutter should be used to cut the straw. The straw should be cut "square" at a 90-degree angle to achieve a good seal with the sheath. The assembled insemination rod is wrapped in a clean paper towel or placed in an insemination sleeve and tucked within clothing for transport to the cow. High conception rates require proper semen handling techniques, the highest quality semen placed in the healthiest cow at just the right time will not produce a calf if semen handling is not performed properly.