Proper semen handling procedures from locating the semen in the liquid nitrogen tank to entering the cow's reproductive tract need review periodically.
Everyone establishes a routine for handling frozen and thawed semen that hopefully does not injure sperm cells and lower conception rates. Usually errors made in the handling semen and the equipment used for artificial insemination are small. However, mistakes in semen handling are frequently additive meaning their effects on semen quality will be magnified.One common mistake that we all make is not concentrating on the task presently being performed. A checklist that I use to review and evaluate semen handling procedures includes individual steps where errors can occur. Listed below are the five areas I most often observe semen handling errors on the farm:
1. Raising the canister containing the semen canes above the frost line of the tank (frost line is usually 4 to 5 inches from the top) and removing the semen from the cane using fingers not tweezers. Exposing frozen semen to elevated temperatures in the neck tube of the tank has the potential to cause sperm damage.
2. Improper thaw bath temperature. Either not using a thermometer to obtain thaw bath temperature of 90ºF to 95ºF or using a thermometer that needs adjustment thus not obtaining desired water bath temperature.
3. Not timing the thawing. Frozen semen should be in 90 to 95ºF water bath for a minimum of 40 seconds for proper thawing.
4. Straw not dried completely prior to placement in the insemination rod.
5. Straw not cut at proper distance from crimp sealed end (middle of air bubble) at a right angle straight across the straw to prevent semen feedback inside the sheath and insemination rod. PD
-- Excerpts from Virginia Tech Dairy Pipeline, Vol. 20, No. 6
Ray Nebel
Senior Reproductive Specialist
rnebel@selectsires.com
