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Artificial Insemination in Cows

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									            Artificial Insemination in Cows
                                   By R. A. McINTOSH*
  A S THERE is a considerable demand for this service from the cattle
     breeders' associations and also from certain breeders who own out-
standing sires in the different breeds of cattle it may be timely to make a
few observations regarding it, the collection of semen, the shipping of it
and insemination.
     Because veterinarians possess specific knowledge of the anatomy of
the genital tract and understand the physiology of reproduction, the breed-
ers of cattle look to them to collect the semen and inseminate the cows to
be bred in this manner. It is probable that it would be advantageous for
practicing veterinarians to undertake this work wherever it is possible for
them to do so for it increases their contacts with their clients and will tend
to increase practice along other lines.
     Credit for the successful accomplishment and the extensive use of this
means of extending the usefulness of outstanding sires must be given to
the Russian technicians who were the first people to undertake it in a large
way. For instance, in 1930, they impregnated 19,970 cows, in 1931, the num-
ber grew to 185,000, in 1932 it increased to 385,000. In 1937, the number of
cows artificially bred had reached 1,000,000 and in 1938, 1,500,000 were re-
ported. From Russia the procedure was taken up by other European coun-
tries and in 1938 the first artificial breeding society in the United States
was organized in the State of New Jersey. Since then many other societies
have been formed in many other states of the Union. The first organized
society of this nature formed in Canada came into existence this last winter
in Waterloo county, Ontario, where a number of Jersey breeders have or-
ganized a project of this kind and bought selectively bred bulls to obtain
semen from.
      Wherever organized projects of this kind are established veterinarians
are engaged to carry out the work of collecting the semen and inseminating
the cows. The fundamental purpose of this procedure is the improvement
 of the livestock, both in conformation and milk production. It has, however,
 other values, and mo.re particularly to rural citizens who are only concerned
in the production of milk. By using artificial means of impregnating their
 cows it eliminates the necessity of them having the bother and expense of
 keeping a herd sire. It is estimated that it costs from 75 to 100 dollars a
 year to feed and care for a bull. Because milk producers only keep the sire
 to impregnate their cows it follows that in many instances they use non-
 descript sires and breed improvement is held in abeyance. On the other
 hand, by the use of seminal fluid from outstanding sires any heifer calves
 they keep to bring into production usefulness will ultimately be better
 producers. Still another value has appeared because of the fact that the
 viability and fertilizing power of the spermatoza may be preserved by
 proper storage and packaging and shipped to distant parts of the country
 and used to inseminate cows for some days after its collection. This feature
 has a commercial aspect for the owners of exceptionally good and outstand-
 ing sires are able to sell semen from such animals at prices ranging from
 $35.00 to $100.00 and perhaps more in some cases. Very naturally the
 owner of such sires seeks to increment his income in this manner. Thus it
 is that the agitation for artificial insemination has grown.
  *   Ontario Veterinary College, Guelph, Ont.

                                                 [239]
 2401 Comparative Medicine   Artificial Insemination in Cows   August, 1942
I20 Ccanadian Joumal
                       of
                                    VI-No. &
                             AriiilVol.

    The proponents of artificial insemination also refer to other advan-
tages such as the usefulness of superior sires may be increased many-fold,
the danger of spreading genital disease is materially reduced, young heifers
and small cows may conceive to large heavy bulls thus eliminating the dan-
ger of natural breeding under such circumstances. In most instances better
breeding and calving records will be kept. Line breeding and the develop-
ment of certain large families of superior cattle within a comunity is
possible. The mating of outstanding individuals, though hundreds of miles
apart is possible. Occasionally shy breeders failing to conceive by natural
breeding can be successfully impregnated by artificial insemination.
     There are some disadvantages also. It requires a well-trained operator
and special equipment. It requires somewhat more time than natural service,
thereby tending to limit its use. All equipment, instruments etc., must be
kept clean and properly cared for and the accomplishment of the work
should be carried out in a sanitary manner to minimize the danger of in-
fection.
     The extended use of sires in this manner will result in fewer pur-
chases of bulls by small breeders and curtail the income of those engaged
in the production of breeding stock.
     Artificial insemination has been used in all species of domestic ani-
mals - mares, cows, sows, sheep, dogs, and even fowls. There are no species
however in which it can be as successfully accomplished as in the cow.
In well-conducted artificial insemination projects the number of concep-
tions are as great as occur by natural breeding.
     The collection of semen is accomplished by the use of an artificial
vagina which is applied to the penis at the time the bull mounts the cow and
the ejaculate is deposited in it. The amount of semen collected averages
about 4 or 5 ccs. In normal bulls this amount of semen will contain millions
of spermatozoa and if a considerable number of cows are to breed at that
time it may be diluted in a suitable dilutor and used in this diluted form
to inseminate the cows. If it is to be used inside of two or three hours after
collection there is no need of refrigeration. On the other hand if its use is
delayed over that length of time it should be placed in a thermos bottle and
kept at a temperature of 45°Fah. When using refrigerated semen the tem-
perature of it should be gradually brought back to body heat before in-
 semination. Exposure to air and repeated cooling and warming of the
semen tends to lower the viability and fertilizing power of spermatozoa.
      When seminal fluid is to be shipped it must be put in suitable air-tight
 containers, packaged in a thermos bottle of 45' Fah. and sent as quickly of as
 possible. For great distances air-mail is used. The fertilizing power
 spermatozoa cared for in this manner is known to persist as long as ac-     96
 hours.  Obviously however, the sooner artificial insemination can be
 complished after the collection of the semen, the greater the likelihood
 of conception.
      The insemination of the cow is accomplished with the use of a twenty
 inch pipette attached to a 5 cc. glass hypodermic syringe by a short rubber
 adapter. The dose about 1 cc. is drawn up into the pipette. The external
 genitals are sponged off and the vagina douched with a physiological sa-
 line solution if thought necessary, then the free end of the pipette is
                                                                   the cervical
 carried into the vagine, introduced into the vaginal extremity of manifesting
 canal and the dose deposited. Cows should   be inseminated while
 oestrum or within a few hours after its completion. Data indicates that a
'Canadian Jourial of       Artificial Inseminat.on in Cows              August 1942
                                                                                  8    ll
                                                                                      21
Comparative Medicine                                                 VA3. VI-No. 8

greater number of conceptions take place if insemination is performed in
the later stages of oestrum. Cows remain in oestrum from 12 to 36 hours.
Successful fertilization can take place as late as 12 hours after the manifes-
tntion of oestrum has ceased. This is because of the fact that the rupture of
the follicle in cows occurs late in oestrum or some hours afterwards.
     Artificial insemination equipment may be obtained from Dr. H. D.
Nelson of Guelph, Ontario, who is the agent for the Jensen-Salsbery Com-
pany of Kansas City Mo., Canada Representatives Limited, 193-195 Spadina
Avenue, Toronto, and also from the Ketchum Manufacturing Co., of Ot-
tawa, Ontario.
     Detailed literature on the subject may be obtained by writing to the
Extension Service, N.J. State College of Agriculture, Rutgers University,
New Brunswick, N.J., and asking for Extension Bulletin No. 200, or to
Agricultural Experiment Station, College of Agriculture, Columbia, Mis-
souri, and asking for Bulletin No. 407.



                                         *    0    *     -




        Rabies Prophylaxis and Single-Dose Vaccine
      THE PROTECTIVE inoculation of dogs against rabies, if combined
*with other measures, can be of great assistance in preventing the spread of
infection in new areas or eradicating the disease where it has long existed.
     The protective inoculation, however, can only be of value when the
biologic used is fully potent. Unfortunately many of the vaccines are of
questionable value and the methods of testing them have not been al-
together satisfactory.
      A recent important contribution by Webster and Casals' would appear
to throw light on the different factors involved. A summary of their report
is, in part, contained below-
     (a) Dogs due to their variability have a limited value in testing the
comparative potencies of weak rabies vaccines. In order to develop and
test vaccines quantitative methods using mice are necessary. (b) Virus
material for preparing vaccines must titre at least 330 mouse doses per cc.
to be effective. This eliminates culture vaccines and leaves virus contain-
ing brain tissue as the sole potent source of vaccine (with the possible ex-
ception of Plotz's).
     (c) A single injection of non virulent irradiated vaccine (described by
the authors) immunizes mice and dogs effectively against a subsequent
test inoculation of virulent rabies virus and does so to a greater degree
than do other vaccines now obtainable.
  I Webster and Casals, (1942) Jour. exp. Med. 76, No. 2, 185-194.

								
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