to Genetic Improvement
the Ideal Ewe
Therapy for A.I.
Shepherd Instructions and Requirments for AIing
PREPARATION FOR LAI
Martin R. Dally
Super Sire, Ltd.
UPDATED FOR FALL 2017
Essential equipment & supplies needed, if technician
is traveling by air to your location:
(10 or 20 lb tank is ideal)
Laparoscopic AI cradle
2 clean pails
2 clean milk jugs (gallon size plastic
recyclable ones are fine)
Electric sheep shears or clippers (a 13
tooth comb will suffice)
Antibiotic spray for wound
Plenty of paper towels
Long-acting penicillin or other
long-acting antibiotic, with syringes/needles
Table for semen setup
Stool for technician to sit on
Electrical outlets: 2 for AI equipment,
plus one for sheep shears
Area with cement floor, washed if
Shelter from wind and dust17.
Helpers; number depends on how many ewes are being bred,
and how many cradles being used. Normally at least 4 but 5 is better
Desirable but not essential items:
Banamine, especially if doing LAI on older ewes. They may have
stiffer tendons and ligaments and experience discomfort
from restraint in cradle. Banamine provides a more
comfortable recovery period
A warm room for semen preparation if weather is very cold
A space heater
What you MAY need to obtain from Super Sire, Ltd. These can also be
sourced thru online vet supply houses:
CIDRs (controlled internal drug
release); 1 for each ewe (with perhaps a spare in case
a ewe loses one and it can’t be found.) and an
PMS-G OR PG-600. (enough to prepare 400
IU for each ewe)
Super Sire, Ltd prefers PMS-G over PG-600, but either one can be
used. PMS-G is available in vials containing 600 IU
(international units), 6,000 IU or 20,000 IU. The larger
the vial size, the lower the cost per animal dose. The
usual dose per ewe is 400 IU; contact Super Sire for exact
dosages because sheep breed, season, prolificacy of flock,
etc. may indicate adjustment of dose.
The procedures described below are designed to cause the ewe’s
reproductive cycle to be re-set so she will cycle
(ovulate) at the time of introduction of semen by LAI
Upon receipt of your CIDRs & PMS-G or PG-600, keep them away from
sunlight, and refrigerate. Store the CIDRs in a cool place
(less than 85 degrees) away from sunlight, but do not
The CIDR is inserted into the ewe’s vagina and remains there for
between 12-16 days. About 14 days is ideal. The exact time
of day the sponge is inserted is not critical. The CIDR
should be inserted far enough to lie just beyond the bony
ridge a few centimeters inside the vagina. The string will
hang outside the vagina.
Check your ewes frequently for loss of CIDRs, especially during the
first 24 hours, which is when loss is most likely. Maiden
ewes are more likely to lose CIDRs than ewes that have
lambed because the CIDR cannot be inserted as far inside
the vagina in maiden ewes.
If a CIDR is lost during the first 48 hours, re-insert it
immediately. If a CIDR is lost after the first 48 hours,
it may cause problems with synchronization. Re-insert
immediately and keep record of which ewe and what time the
CIDR was re-inserted. The technician will examine the
reproductive tract and will not LAI the ewe if she is not
ready. This will save the semen and unnecessary cost.
To trigger the ewe’s ovaries to prepare for ovulation:
The CIDR is removed
PMS-G (or PG-600) is given
The timing for CIDR removal and administration of the
PMS-G or PG-600 is very critical. You will receive
specific timing instructions.
Timing of hormone injection is arranged so LAI will take
place during a time window between 54 and 61 hours after
PMS-G or PG-600 is given to the ewe. For large flocks
(over 50 ewes) LAI may start at 54 hours, and for smaller
flocks LAI is scheduled at about 58 hours. LAI is timed so
all ewes are bred by 61 hours. Beyond 62 hours conception
rates are lower with fewer viable fetuses.
When using CIDRs (y-shaped devices),
LAI is timed to take place 50-54 hours after CIDR removal
and PMS-G or PG-600 injection. CIDRs contain natural
progesterone, and CIDR removal does not cause a surge of
progesterone in the ewe.
Preparing the PMS-G
(pregnant mare serum gonadotropin)
For each vial of dry, powdered PMS-G you will receive a vial of diluent, which is normal sterile saline solution. To prepare the hormone:
Using a syringe, withdraw 3 – 4 ml (cc) of diluent
Inject this diluent into the vial containing the powder, and rock vial back & forth to mix
Withdraw all of this mixture back into syringe
Inject the mixture into the remaining diluent
Withdraw 3 – 4 of this hormone-diluent mixture and inject it back into vial that contained powder to rinse any remaining hormone out
Pull all of this out of the powder vial and inject it back into diluent vial
Withdraw all the mixed hormone solution to syringe
If you do not have vials of pre-measured diluent:
Use sterile saline solution or sterile water as diluent.
Mix as follows:
For the (6,000 I.U.) vials of PMS-G, add 30 ml diluent to
the dry PMS-G. The resulting solution will contain 200
I.U. of PMS-G per ml. To administer 400 I.U., give 2 ml.
The PMS-G must be used immediately
after mixing; do not mix it ahead of time. Prepare PMS-G
15 minutes prior to pulling CIDRs.
PMS-G is given by
IM (intramuscular) injection. Location of IM injection
is your preference. Super Sire prefers the neck, but hind
leg also can be used.
24 hours before AI, remove feed &
water from your ewes. In cases of extreme hot weather,
remove feed at 24 hours, but leave access to water until
perhaps 22 hours before LAI is scheduled to begin. Some
breeds retain water longer than others. For example, with
Dorper ewes water should be withdrawn 26-28 hr before AI,
but leave feed until 24 hr. before AI.
If ewes are on lush pasture, remove
them from pasture 48 hours before AI and feed them hay
until 24 hours before AI. Pasture feeds are high in water
content, again causing full bladders.
In no circumstances should ewes be more than 34 hours
The reason for removing access to water is a full bladder
prevents visualization of the reproductive tract, and
makes good semen placement very difficult. Feed is removed
because a full rumen may rarely be punctured by the LAI
instruments and because ewes are more comfortable during
AI if they are off feed and water beforehand.
POST-LAI CARE OF EWES
Immediately following LAI, the ewe
should be taken off the cradle and released into a holding
pen or pasture with feed and water. It’s very important
that ewes are not stressed after AI, and that they begin
to eat right away.
is extremely important to minimize stress of the ewes
during the hormone therapy program as well as the first 32
days after insemination. Dogs should never be used to work the ewe and any unnecessary movement
of the ewes is strongly discouraged. Heat stress can
affect conception rates; therefore the ewes should have
access to shade and clean water at all times.
Feeding high levels of concentrates after inseminating has
been reported to cause lower conception rates. Therefore,
it is recommended to decrease the level of concentrates
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