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Artificial Insemination in Cattle
advisability of using semen stored for long
periods is questionable in view of the low ratio
pregnancies which results therefrom.
The practical limits of storage for semen are
24 to 48 hours; and, provided the semen shows
good motility at the time of insemination, the
rate of conception should approximate to that
of normal service.
8. DILUTION OF SEMEN
It is emphasized that dilution of semen should
be avoided except when it is necessary to in-
seminate a large number of animals from a
single ejaculate, as, for example, in large-scale
artificial insemination schemes. The undiluted
ejaculate can generally be utilized for the in-
semination of about three to five cows. The
addition of a suitable diluent increases the
number of cows which may be inseminated from
one ejaculate to about ten.
Special diluting solutions ready for use can
be purchased from firms specializing in the
supply of apparatus for artificial insemination.
9. NOTES ON THE CLEARING OF APPARATUS.
Artificial Vagina. Before use, new inner
timings should be turned
inside out and
linings should be turned inside out and
washing soda has been added.
They should then be rinsed thoroughly in run-
ning water to remove all trace of soda and then
hung up to dry.
After use, the vaseline which is used as a
lubricant must be removed as soon as possible
otherwise it tends to 'perish' the rubber. To
do this, place A.V. in a bucket containing hot
water and washing soda; then with a bottle
brush (24 inches long) thoroughly cleanse the
inside of the liner. Rinse in water and then
swab the liner with a piece of cotton wool or
rag soaked in 65 per cent. alcohol; the swab is
held in an 18-inch swab-holder.
Syringes collecting cups, etc. Wash all
glassware, new and after use, first in cold
water, then in hot water and washing soda.
Rinse in running water, followed by 65 per cent
alcohol. Allow to become thoroughly dry before
use by standing on blotting paper or by placing
on a warm oven or hot tank.
When not in use all the apparatus should be
protected from dust.
10. LIST OF APPARATUS AND INSTRUMENTS
The following is a list of the minimum appa-
ratus required in connection with artificial in-
semination work. For particulars of prices, the
usual firms supplying veterinary instruments
should be consulted:
For Collection of semen. One A.V. complete
with inner liner and collecting cup; two spare
liners; three spare collecting cups.
For Injection of semen. One insemination
syringe with spare parts (various patterns).
Alternatively, capsules and gun. Speculum;
torch or headlamp.
For storage and transport of semen. One
dozen Pyrex glass sperm storage tubes (5 c.c.).
One dozen glass containers with flat bottom to
take the storage tubes. One thermos food jar
or flask. One wooden box to hold thermos if
this is to be sent by rail etc.
For cleaning the apparatus. One bottle brush
(24 inches); 1 swab holder (18 inches). Small
bottle brush for cleaning sperm tubes.
BIBLIOGRAPHY
EDWARDS, J. WALTON, A. (1938.)
New
Service
Crate. Emp. F. Exp. Agric. 6. 206.
HERMAN, H.A., and SWANSON, E. W. (1941.) Variations
in Dairy Bull Semen with respect to its Use in Arti-
ficial Insemination. Res. Bull. 32 Agric. Exp. Sta.,
Univ. of Miss.
LAMBERT, W. V., and MCKEBZIE, F. F. (1940.) Artifi-
cial Insemination in Livestock Breeding. Circ.
567 U.S. Dept. Agric., Washington.
WALTON, A. (1933.)
The Technique of Artificial
Insemination. Publ. Imp. Bureau Anim. Genetics.
—(1942.)
Notes on the Artificial Insemina-
tion of Sheep, Cows and Horses. 3rd edit. London.
ADDENDUM
Technique of making sperm counts
To estimate the number of spermatozoa in a unit
volume of semen the latter must be suitably diluted
as that individual spermatozoa may be counted in a
cytometer. The Fuchs-Rosenthal and Thoma-Zeiss
types are suitable.
A. USING THE FUCHS-ROSENTHAL CYTOMETER
It is necessary to make a preliminary examination
under a 2/3 objective to estimate a suitable dilution of
the sperm to simplify the counting.
The Fuchs-Rosenthal cytometer is graduated so that
the depth of the counting chamber is 0.2 mm. and the
area of each small square 1/16 sq. mm.
The sample of semen is well mixed, 0.1 c.c. of semen
withdrawn with a fine-bore pipette and added to 9.9 c.c.
of normal saline and the resulting suspension well
mixed. This gives a dilution of 1 in 100.
For accuracy, it is advisable to have only about five
spermatozoa to count in each small square in the
cytometer.
This usually necessitates a final dilution of 1 in 800
to 1 in 1,600. The further dilutions are made in
multiples of eight, to simplify the final calculation of
density per cu. mm.
To convert the 1 in 100 suspensions to 1 in 800, take
1 c.c. of the 1 in 100 and add 7 c.c. of normal saline.
At each stage in dilution, the suspensions must be well
mixed. The coverslip is placed in position on the cyto-
meter and a drop of the diluted semen is introduced
with a pipette under the coverslip and allowed to run
in so that it just fills the counting chamber.