notes that some vets in rural areas may be unwilling or unable to commit to using frozen semen because of the travel logistics which go along with the increased need to more closely monitor mares being bred with frozen. “If you have to drive your mare a few hours to an experi- enced vet with a clinic, then that may be the best way to go,” she advises. Frozen semen is also infinitely more fragile than fresh semen and must be handled carefully. Exposing frozen semen to conditions outside the storage tank for even a few seconds can cause irreparable damage, for example. Because of this, veterinarians must be very careful when handling or thaw- ing frozen semen. Many will only inseminate with frozen semen at their own facilities with their own laboratories, which can be incon- venient for mare owners, espe- cially those who are accustomed to having their veterinarian come to their farm to inseminate with fresh-shipped semen. Most frozen semen tends to be sold without a “live foal guaran- tee” (LFG), whereas a LFG is usu- ally standard with fresh-shipped semen. The lack of a LFG can also make some breeders hesitant to try frozen semen. Carol has also noticed that
35 mm and then she is given an ovulation-inducing agent such as hCG or Deslorelin. Then, instead of ultra- sounding every six hours, the mare is inseminated 24 hours after the hCG or Deslorelin was administered and again 16 hours later (40 hours after the ovulation-induc- ing drug was administered). “This protocol seems to be just as successful as the
old way, and it’s much easier on vets,” says Carol Aus- tin, who adds she has noticed veterinarians becoming more comfortable with frozen semen in general. Be- cause the two-dose timed in- semination protocol requires fewer palpations and ultra- sounds, it makes the process easier for mare owners who pre- fer to keep their mares at their own farms instead of taking them to a vet clinic.
Finding a Veterinarian Before mare owners make plans to breed with frozen semen, it is critical to find a veterinarian who is not only experienced in equine reproduction but also has experience specifically with frozen semen. Mare owners, you should
some breeders like to use stallions they’re able to see in person, which can rule out both European and de- ceased stallions. The breeders who prefer domestic stal- lions tend to opt for fresh shipped semen, since that is an option offered by most stallion owners/managers.
New Protocol Ideally mares should be inseminated with frozen semen within twelve hours before or six hours after ovulation. Previously standard practice was to palpate or ultra- sound the mare daily until her follicle reaches 35 mm and then continue to ultrasound every six hours (four times a day) until she ovulates—which could be days later. This resulted in numerous palpations and ultra- sounds and was very time consuming for the veterinar- ian, and therefore expensive for mare owners. Now, however, the two-dose timed insemination
protocol has become much more common. (Variations, such as using the timed insemination protocol but split- ting a dose instead of using two doses, are also com- mon.) With the timed insemination protocol the mare is palpated or ultrasounded daily until her follicle reaches
76 January/February 2015
Preparing a shipment of frozen straws in a dry vapor shipper.
not be afraid to politely inquire about a veterinarian’s experi- ence and willingness to work with frozen semen. Determine if you’d prefer to leave your mare at a clinic or if you’d prefer to
have the veterinarian come to your farm, and inquire as to whether they have a clinic and/or whether they are willing to make farm calls for frozen semen breeding. It is also a good idea to inquire about costs beforehand as the costs of breeding with frozen semen can add up even more quickly than the costs of breeding with fresh semen.
Theriogenologists vs. General
Practice Veterinarians Many general practice equine veterinarians are will- ing to inseminate with fresh semen but are not as likely to work with frozen semen, usually because of the ex- tra time and/or experience required. In contrast, most equine theriogenologists (veterinarians who special- ize in equine reproduction) will happily work with fro- zen semen. Reproduction specialists are also likely to be more accessible than general practice veterinarians because they’re unlikely to be called away for a colic or other emergencies.
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