Insemination of University of Wisconsin-Madison Frozen Equine Semen

Mare Selection

1. The mare should be ±6 hr from ovulation at the time of breeding for optimal success.  If the mare is bred before ovulation, recheck the mare approx. 12 - 18 hours after breeding with ultrasound or rectal palpation and rebreed if she has not ovulated.
2. Routinely we now induce ovulation with HCG at >35 mm follicle and inseminate at both 24 and 36 hours after HCG.  We check the mare at 48 hours after HCG to ensure ovulation has occurred.  Likely if she has not ovulated you should try in another cycle. The same can be done with Desorelin and >30 mm follicle.

Semen Thawing

1. Warm 10 ml of IMV breeding buffer to 37°C (98°F).  Be sure the breeding buffer is at this temperature before proceeding further.
   
2. Thaw 7 straws of semen at 37°C (98°F) for 60 seconds.  Dry the straws, cut one end of each straw (near orange plug end), place straw over tube of breeding buffer and cut other end of straw to allow it to drain into tube.  Blow any remaining semen into the breeding buffer.  Repeat the procedure for each straw.
   
3. Hold the semen in the breeding buffer for at least 10 minutes before insemination.
   
4. Fill the insemination pipet or syringe with the semen in the breeding buffer (approx. 14 ml) and inseminate the mare using normal procedures.