Equine
Reproduction
Reading
Assignment: Refer to chapters 12, 14 and
17 in Manual of Reproduction
A. Special facility is generally made available.
1. Collection area should be:
a. Clean and safe with good footing.
b. Need a phantom or dummy “mare”.
c. Working area needs to be in close proximity to laboratory.
d. Restraint equipment (hobbles, twitch, etc.) should be well
organized
and handy.
e. Cleaning and
collection supplies for stallion and mare:
1. Each stallion should have separate buckets.
2. Artificial vagina and parts: water holding cylinder with handle,
inner
removable liner, collection bottle with filter to trap gel
fraction,
thermal covering for collection bottle.
2. Laboratory shall contain:
a. Microscope and slide warmer.
b. Incubator (100 degrees).
c. Refrigerator and freezer.
d. Autoclave.
e. Artificial vagina (see above).
f. Spectrophotometer or hemacytometer
(used to check for concentration of semen –sperm per ml.)
g. Various pipettes, measuring cylinders and test tubes, as well
as, other miscellaneous laboratory equipment.
3. Mare handling area:
a. One or two chutes.
b. Preferably in close proximity to the laboratory and
collection area.
c. Cleaning and breeding supplies for insemination process.
1. Nolvasan solution
and scrub.
2. Insemination set (sterile pipette, syringe, and ob sleeve).
3. Tail wrap.
4. Sterile KY lube.
B. Collection Procedure:
1. Have AV ready and at correct temperature (42- 45 degrees
centigrade).
2. Bring stallion into collection area, when penis is erect, one
person should be responsible for washing the penis before mounting. Normally a
mild soap and water is used such as ivory bar soap. Rinsing thoroughly is very
important to remove all residue. (Some farms choose to use clear water
only). Make sure wash water is warm.
3. Allow stallion to mount the phantom or live mare and the
collector should carefully, but quickly deflect the penis into the AV.
4. The stallion will thrust usually no more than 30 seconds
and then ejaculate. (Pulsating of the urethra or flagging of the tail).
5. As the stallion dismounts, slowly tilt the AV downwards
toward the collection bottle and take to laboratory for evaluation.
C. Semen evaluation procedure:
1. Separate gel fraction from sample and discard gel fraction.
2. Pour gel free fraction into warmed graduated cylinder to
check VOLUME.
3. Take sample of gel free semen to check for MOTILITY,
MORPHOLOGY AND LIVE/DEAD RATIO under microscope.
4. Take sample of gel free semen to check for CONCENTRATION
(sperm per milliliter).
5. Mare
must receive minimum of 500 million progressively motile sperm per
insemination.
6. Semen extender (milk based mixture often with antibiotics
that will make for easier handling of sperm and extend the life of the sperm
cells.
7. Load warmed sterile syringe with at least 500 million
progressively motile sperm. (Example: 50% progressive motility of sample, 250
million sperm per ml. (or cc). Add
extender in equal parts, (25 ml. extender added to 25 ml. of semen). Use 8 cc
or 8 ml. per mare. Total extended volume of 50 ml. can inseminate 6 mares.
(6X8=48)
D. Insemination procedure:
1. Bring mare into stocks (if foal is by side, have foal stock
also).
2. Use Nolvasan scrub to wash
perineal area. Rinse with clear water.
3. Wrap tail or have one person responsible for holding tail out
of the way.
4. Introduce warmed sterile pipette through cervix and into
vagina using sterile sleeve on arm.
5. Slowly introduce (inject) extended semen into pipette and
follow with air.
6. Go on to next mare.
A. Sending from stallion:
1. Normal collection procedure.
2. Determine insemination dose for single mare (500 million
progressively motile sperm).
3. Prepare 2 doses.
4. Place into equitainer or similar device
which will cool semen to 4-8 degrees centigrade. (This is the same as a normal
refrigerator.)
5. Ship to destination via air transport. (Usually arrives
within 24 hours.) Semen will be viable
for up to 72 hours.
B. Arriving for mare:
1. Have courier pick up from airport.
2. Preplanning should leave you with a mare that is in estrus
and ready to ovulate within 24 to 48 hours.
3. Inseminate mare with one dose immediately and one dose
within the next 24 to 48 hours depending on ovulation determination.
4. HCG (human chorionic gonadatropin)
often used to stimulate the mare to ovulate within 24 to 48 hours.
C. Use of Frozen semen:
1. This technique is successful, but is not as successful as
using cooled, shipped semen. The technique is being perfected and may eventually
take over the shipment of cooled semen, which would allow for much less
preplanning and deadlines.
A. Definition – the process of removing a fertilized ovum from a donor
mare and
introducing
it into a recipient mare’s uterus for the recipient mare to carry to term.
B. Procedure:
1. Requires the synchronization of the estrous cycles of the donor mare
and the
recipient
mare.
a. Often accomplished by use of prostaglandin injection to
each mare at the same time during their diestrus
period.
b. Each mare should come into estrus by the third day after
injection.
2. The donor mare is bred to
the stallion and 7 or 8 days after she ovulates, her
uterus
is flushed using approximately 3 liters of specialized solution.
3. The embryo is recovered using gravity (embryo settles to bottom of
fluid) and is
identified
under microscope.
4. Embryo is transferred to
recipient mare, which should be approximately 7 to 8
days
from ovulation.
a. Non-surgical transfer would go through the cervix into the recipient
mare
similar to the semen insemination technique. This technique
has
not proven as successful as the surgical technique so is not
used
very extensively.
b. The surgical transfer of the embryo involves an incision in the
flank
of the mare and the location of the uterus. The embryo is
introduced
into the uterus through a large bore needle puncture
into the uterus.
c. Success rate is 65 – 75 per
cent for the surgical technique.
ASSIGNMENT:
Please send to jsales@horsecoursesonline.com "Lesson 9 Repro" in subject
line.
1. Briefly and in your own words, give advantages and disadvantages of
using artificial insemination.
2. Describe important components of a breeding shed to be used in an
equine artificial insemination program.
3. What are the most common reasons for performing embryo transfer in the
mare?