A technique to chemically ejaculate stallions was recently developed and published. Advantages to chemical ejaculation over current collection procedures include:

  • Chemical ejaculation is technically easier and less time-consuming
  • Chemical ejaculation does not adversely affect behavior of the stallion (since he does not realize that he’s breeding)
  • It poses less risk of injury to the stallion, mare, and personnel involved
  • It is very useful for stallions that are physically incapable or have difficulty mounting a phantom or mare
  • Special handling facilities are not required
  • Special equipment is not required (such as a phantom mare, artificial vagina, etc.)
  • The procedure is relatively inexpensive
  • Samples are generally very concentrated and can be extended to breed multiple mares
  • There are apparently no long-term adverse side effects associated with the medication(s)

The primary disadvantage to the procedure is that it appears to work only about 60% of the time. Therefore, we recommend a "trial run" for each stallion prior to collecting semen for insemination and/or shipping. During the trial, ejaculation success as well as an effective protocol for collection (which may differ for each stallion) should be determined.

Following is a step-by step description of the procedure for chemically collecting stallions. The procedure is best performed in a calm, quiet place without distraction (e.g. the stall). Since each stallion is different, different combinations within each step should be tried to determine the most effective approach for each stallion. The approximate cost of Imipramine is $0.35 per tablet or $28 for 100 tablets. Each tablet contains 25mg Imipramine. The approximate cost of Xylazine is $5.00 per cc.

STEP 1:
Administer Imipramine at a dose of 1-2 mg/kg (20-40 tablets for a 1000# horse) orally approximately 1-2 hours prior to collection. The medication can be administered with the feed or crushed up and injected into the mouth with a syringe. All of the medication should be consumed.

STEP 2:
Prestimulate the stallion approximately 15 minutes prior to collection. This can be achieved by the use of an estrus mare, urine-soaked bedding, or a urine-soaked rag. It should be noted that some stallions perform better when they are not prestimulated.

STEP 3:
Allow the stallion to completely calm down and relax prior to STEP 4.

STEP 4:
Administer Xylazine at a dose of 0.3+ mg/kg (1.5-2.5 cc for a 1000# horse) intravenously. If an adequate level of sedation is not achieved, administer another 0.5-1.0 cc intravenously.

STEP 5:
Collect the stallion. A collection device can be fabricated by placing an appropriate lightweight container placed in a wire coat hanger bent in a circular fashion. Ejaculation should occur within 15 minutes of Xylazine administration. Try not to excite the stallion during the collection procedure.

STEP 6:
Evaluate and prepare the semen for insemination/shipping. Since the sample is concentrated and does not contain a lot of accessory fluids, use of an extender is recommended.

Contributed By: http://www.atlantaequine.com/