Stallion Collection & Evaluation
One of the many procedures done at Dakota Large Animal Clinic is collecting a stallion’s
semen and evaluating it. With the advances made in the past years in equine
reproduction, a stallion still has to be fertile to get a mare pregnant.
We use an artificial vagina (A.V.) to collect a sample of semen for evaluation. Often
times we can train the stallion to mount a phantom with a mare in heat near by to arouse
him. Many variables are taken into account: anything that comes in contact with the
semen must be warmed to 37 degrees Celsius prior to collection. We train the stallion to
be washed with warm water (but no soap) prior to collection. This aids in stimulating the
stallion’s libido and preventing contamination of a sample.
After the sample is collected, our technicians head to the lab where we maintain the
sample at 37 degrees Celsius while we count the concentration of the sample, measure
the volume collected and estimate the motility of the sperm. Remember motility does not
equal fertility – the best guarantee of fertility is a positive pregnancy – but we can get a
good idea if the stallion should be able to get a mare pregnant with these evaluation. If
the stallion’s semen is going to be shipped somewhere, we will package samples in
different extenders to prolong its viability, then at 24 and 48 hours we evaluate the
motility of the samples to determine which extender works best for that stallion.
Everything is documented for that stallion for future use. We record what type of A-V the
horse prefers, the “tightness” of the A-V and the temperatures he likes best. We want to
satisfy the stallion as best as we can to get the best sample we can.
We also document all the measurements made; including the pH of the semen sample,
total volume, concentration and total sperm output. A slide is also made to determine
morphology of the spermatozoa making sure there are no abnormalities to note.