Animal Reproduction (A.I.)
College of Natural Resources
unnecessarily prolonging the dry
period.
ARTIFICIAL INSEMINATION
Artificial insemination is the deposition of
male reproductive cells (spermatozoa) in
the female reproductive tract by
mechanical means rather than by natural
mating.
The success of the insemination depends
mainly upon i) the inherent fertility of the
sperm, (ii) proper handling of the semen
prior to insemination, (iii) insemination at
the right time during oestrus, and (iv)
proper semen deposition.
Advantages of A. I. over Natural
Breeding
1. The main advantage of A.I. is that
it increases the usefulness of
superior sire to an extraordinary
degree. It makes available sires of
inheritance for milk and butter fat
production to all dairymen within a
limited area. Previously only a few
could get the advantage of good
bulls.
2. The services of superior sires are
greatly extended. By natural
services, a bull can be bred to 50 to
60 cows per year; on the contrary
New York Artificial Breeders
Co-operative have sired 10,000 in
one year by one bull. It would have
taken about 200 years to
accomplish this by natural service
of that bull.
3. The breeder does not need to
maintain a herd sire and thus can
avoid the botheration accompanied
with the management of a bull. It
helps to regulate the breeding
programme and the space between
successive
calving
without
Prepared by Tshewang Dorji
4.
The dairyman does not have the
problem
of
searching
and
purchasing a new herd sire every
two years to avoid inbreeding.
5.
The technique of A.I. can be made
use of in cross breeding for hybrid
vigour by quickly transporting the
semen by air to different
continents.
6.
The intensity of the spread of
genital diseases is lessened if the
specially trained persons conduct
A. I. under complete sanitary
conditions.
7.
Overcomes the difficulty of size
and weight.
8.
Increases rate of conception,
9.
Outstanding animals located apart
can be mated.
10. Helps in better record keeping.
11. Old heavy and injured sires can be
used with advantages.
Limitations of A.I.
1. Requires well-trained operations
and special equipments.
2. Requires more time than the natural
services.
3. Necessitates the knowledge of
structure
and
function
of
reproduction, on the part of the
operator.
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Animal Reproduction (A.I.)
4. Improper
cleaning
of
the
instruments
and
unsanitary
conditions may lead to lower fertility.
5. Market for the bulls is reduced while
that for the superior germ plasm is
increased.
6. Selection of the sire should be very
rigid in all respect.
Detection of Oestrus and Time of
Insemination in Cow
Maximum fertility will be achieved by
having highly fertile sperm present in the
oviducts when ovulation occurs. Since the
life of the ovum is relatively short. about
two hours, the sperm should reach
sufficiently ahead of ovulation to effect
proper fertilisation Thus insemination
should precede ovulation. Ovulation time
is difficult to determine routinely, so
inseminations should be timed from the
onset of oestrus. Checks for oestrus must
be done carefully and regularly. Usually
cows come in oestrus condition after
every 21 days if non-pregnant. In case
one fails to detect oestrus for the first
time, he may be very careful on and from
19th day to 21st day after the failure to
detect oestrus on the first time. In the
cows, oestrus is indicated when the
female stands to be mounted by another
animal. Cows first seen in oestrus, in the
morning should be inseminated the
afternoon of the same day; those first
observed in oestrus in the afternoon
should be inseminated the next morning.
The stimulus of insemination may reducethe interval from the end of oestrus to
ovulation.
Site of semen deposition.
Prepared by Tshewang Dorji
College of Natural Resources
In the cow the best fertility can be
obtained with the recto-vaginal technique.
A gloved hand is inserted into the rectum
of the cow and used to pick up the cervix
and thus the rectal wall. An inseminating
tube is then inserted into the vagina and is
guided into or through the cervix by
means of the gloved hand in the rectum.
Sufficient practice is necessary before an
individual becomes proficient at this
technique. Some kind of non-irritating
lubricant should be used on the gloved
hand. Applying some of the lubricant to
the anal region prior to the insertion of the
cupped hand through the anal
musculature is advisable. Insertion of the
inseminating tube into the vagina should
be started with the tip pointed upward at
an angle of 20-30 degrees. This avoids
the possibility of having the tip enter the
blind pouch or urethral opening. The
gloved hand in the rectum should be used
to follow the tip of the inseminating tube
as it is gently pushed into the vagina, for
the tube will serve as a guide in locating
the cervix. Deposition of the semen
through the cervix and in the anterior
portion of the cervix is recommended.
THE EQUIPMENT YOU WILL USE:
Storage container
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Animal Reproduction (A.I.)
Aluminium or stainless steel vacuum
vessel used to hold semen and Liquid
Nitrogen
College of Natural Resources
Insemination must be done properly and
this is essential for any A.I. operation.
Techniques:
Canister:
Removable cylinder with mesh-bottom to
hold semen in the containers. Has a long
hooked handle to permit identification and
access from the mouth of the container.
Goblet:
Plastic cylinder with liquid-proof bottom
that fits into but is half the height of the
normal canister. This allows two layers of
semen storage. Straws to be kept for
longer than a few weeks should be held
on the bottom layer.
1. Speculum method
2. Recto-vaginal method
The most commonly used technique
throughout the world is the Recto-vaginal
technique.
The speculum method was found in
favour earlier because little experience
was needed but there were certain
Straws:
Each straw contains one cow dose. The
volume of a straw is 0.5 cc for the
medium-straw and 0.25 cc for the
mini-straw.
Manufacturer’s end of straw:
During manufacture the straw has a
double wad and powder plug fitted. This
eventually seals one end of the straw
(when the powder is moistened during
filling). It also acts as the piston that
pushes the semen out of the straw when
the inseminator depresses the plunger of
the gun.
After filling in the processing laboratory,
the powder seals the straw. The powder
may be of varying colours and is generally
from 3 to 8 mm long. The inseminator cuts
off the seal during the loading of the
insemination gun.
serious drawbacks. One of these was the
need for cleaning and sterilizing the
speculum after each insemination. The
conception rates are not as good as they
are with the recto-vaginal technique.
The Recto-vaginal technique on the other
hand requires considerable practice
before proficiency is reached.
Proper
involve:

insemination
techniques
Proper identification of the cow before
insemination
INSEMINATION TECHNIQUES:
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Animal Reproduction (A.I.)

Interrogating the farmer in order to
obtain a clear picture about the history
of the cow.

External examination of the cow to be
inseminated

Proper selection of the semen

Application
of
correct thawing
techniques there frozen semen is
used

Proper preparation of the insemination
gun.

Hygienic handling of insemination gun
and animal

Thorough rectal examination of
vagina, cervix and uterus before
actual insemination

Proper introduction of the gun into the
cervix

Deposition of the semen at the right
spot in the genital tract of the cow

Careful approach and handling of the
cow during insemination
Proper recording of A.I. in the A.I.
register

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observation by the owner. Cows should
not be inseminated within 60 days after
normal calving and not within 90 days in
case of an abnormal calving or in case of
abnormalities after calving. Animals that
have shown abnormal discharge from the
vulva in the three weeks period prior to
present insemination should also be
refused.
2.
The next thing to do is the external
examination of the animal:

The tail, the vulva and adjacent parts
should be carefully checked for the
presence of mucous or purulent
discharge

Are there signs of standing heat on the
rump or the tail head - a cow that has
been mounted is likely to show mud or
scars on these areas

Open the lips of the vulva with the
fingers and check the clitoris and the
mucous membranes; in case of
abnormal discharge, flocks of pus are
likely to be detected on the clitoris.

Animals that show abnormalities in
external examination should be
refused
for
insemination
and
necessary treatment should be carried
out.
Proper cleaning and handling of all
materials and equipment
3.
1.
The History of Animal:
Before
starting
with
the
actual
insemination, the person presenting the
cow should be asked about when the cow
calved and whether any abnormal
discharge or abnormal behaviour was
noticed. Also get the information on heat
Prepared by Tshewang Dorji
External Examination:
Rectal Palpation of Cow:

One hand is gloved and the glove is
lubricated with a special non-irritating
lubricant

Make the gloved hand into cone
shape and insert in the rectum with
gentle movement
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Animal Reproduction (A.I.)

If necessary, remove the dung from
the rectum by gently back racking

Carefully palpate the cervix and the
two uterine horns; if the cervix is soft
and pliable and if the uterine horns are
rigid and contract on palpation
(Tonicity), the cow is definitely in heat
However, if the cervix is hard and rigid
and the uterine horns soft and flabby it
is unlikely that the animal is in heat

The uterine horn should be carefully
checked for endometritis, pregnancy
or abnormalities
College of Natural Resources
bring the canister up to the top of the
neck.

The goblet may be raised to the top of
the canister by using forceps. The
goblet should be always full of liquid
nitrogen. Pick up a straw and return
the goblet to the bottom of the canister
and return the canister to the bottom
of the container in the correct position

Shake the straw and place it in the
thawing water for 30 seconds

Replace the neck plug in the container
Cows with abnormalities or without
obvious heat signs should never be
inseminated

Thawed straw should be used within
20 minutes and once thawed, a straw
should not be frozen
Avoid touching the ovaries during
rectal palpation; palpation of the
ovaries of cows in heat can provide
rupture of the follicle and then the cow
will no longer be able to conceive
Step I - Thawing of Straw:

Remove straw from water and gently
dry with tissue paper or clean towel
Make final identification of straw



Warm water at 32 to 38 degrees
Centigrade. It is essential to use a
thermometer. Dipping a finger into the
water is not reliable.

Thawing water above 40 degrees
Centigrade may kill the spermatozoa

Remove the neck plug from the
storage container

Select the canister containing the
semen required. Lift the canister hook
and swing canister to the centre
position

Lift the canister to the top of the frost
line in the neck of the container (50
mm below the top of the neck). Do not
Prepared by Tshewang Dorji

Step II - Loading the Gun:

Pull the plunger of the gun 10 cm out
of the gun

Push the manufacturer’s end (double
wad end) of the straw into the
insemination gun as far as it goes.
This should leave the straw protrude
about 3.5 cm

Hold the loaded gun vertical at eyelevel and with clean sharp scissors
make a horizontal cut 1 cm off the tip
of straw to remove the laboratory seal.
The cut must be at right angle to the
straw to ensure a perfect seal between
the straw and the outer sheath

Remove a sheath from a protective
container and place it over the barrel
of the gun. The function of the sheath
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Animal Reproduction (A.I.)
is to prevent contamination of the gun
and to hold the straw in place during
expulsion of the semen. Fit the sheath
over the gun and through the “O” ring.
The sheath is slit at its bottom to fit
over the enlarged portion of the A.I.
gun. Push sheath firmly onto the
enlarged portion of the gun using a
sensible amount of force and push the
plastic ring tightly over the sheath and
the A.I. gun.
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College of Natural Resources

Thoroughly clean the vulva of all soap,
dung and dirt by wiping with a clean
tissue paper

Grasp the cervix and pull it slightly
towards you so that vulval lips open.
Then guide the gun through the vulva
into the vagina. It may be necessary to
push the cervix forward to straighten
any vaginal folds

When the gun reaches the external os
of the cervix, hold the cervix firmly then
try to thread the cervix over the gun. It
will probably be necessary to move
the cervix slightly in order to find the
opening. Never do more with the
cervix than is necessary to get the job
done. Use minimum strength and
minimum of movements - all smooth
and gentle. Make all movements
purposeful. Try not to fumble or do
anything without specific reason.

In case of first insemination the semen
should be deposited just in front it the
internal os or in the mix cervix. The
gun should not enter the uterus as this
can cause serious injury to the uterine
wall.

In case of repeat insemination there is
the possibility that a cow is actually
pregnant.
Therefore,
it
is
recommended to deposit the semen
at the external of and not to pass the
cervix completely

Deposit the semen by depressing the
plunger slowly on third of the dose in
the internal os and remaining two
thirds in the mid cervix

Pause before withdrawal to allow the
semen to get away from the gun, then
slowly withdraw the gun from the
Slowly and firmly move the piston up
the gun until the movement of the
semen at the tip is seen. Be careful
not to expel the semen. You are now
ready to proceed with the actual
insemination
Step III - Inseminating the Cow:


Put a disposable glove on the left
hand and wet the gloved hand and are
by dipping into a bucket of clean
water, then allowing to run back down
the are. Apply a small quantity of liquid
soap or lubricant
Carry the loaded insemination gun in
the mouth. Be sure the end of the gun
does not become contaminated by
contact with projecting objects or
walls. Also take care not to bump the
plunger on a wall or post while
inserting the hand into the rectum of
the cow

Make the cow aware of your approach

Protect the hand from contamination
with a piece of paper, then take a firm
hold of the cow’s tail and lift it aside
Insert the hand into the rectum and
remove the dung by back racking

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Animal Reproduction (A.I.)

College of Natural Resources
cervix because a rapid withdrawal can
suck the semen back through the
cervix and into the vagina
Slowly withdraw the hand from the
rectum of the cow

Remove the soiled sheath from the
gun after loosening the “O” ring. Do
not allow the ring to contact the soiled
part of the sheath. Slide the sheath
from under the lock ring and remove it
from the gun. The empty straw should
come out with the sheath

Dispose of the straw, sheath and dirty
glove in a waste bin. Do not leave
them lying around

Reasonable care should prevent the
unprotected parts of the gun from
being contaminated. If these parts
become soiled with dung or mucus the
gun should be put aside until it can be
thoroughly cleaned

After completing all inseminations the
following cleaning procedure should
be carried out.
Dispose of used sheaths, paper and
plastic gloves, leave the soiled
equipment behind


Place any contaminated guns aside
for through cleaning before use

Wash
hands
non-gloved hand
particularly
After insemination, fill in the A.I. register
provided to each A.I. Centre.
the
Keep your A.I. kit clean and tidy at all
times and wash it thoroughly at
regular intervals. Guns should be
washed and rinsed at least once a
week.
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