|
Q2) What are the advantages and disadvantages of
artificial insemination versus live cover?
There are many issues to consider when making the decision of live cover
verses artificial insemination. For some breeders the choice is already made for
them. For example, in order for the resulting foal to be registered with The
Jockey Club, Thoroughbred breeders must have their mares bred by live cover.
As inconvenient as this might seem to those unfamiliar with the Thoroughbred
industry, this policy ensures the ability of more colts to end up at stud. If
Thoroughbred mare owners weren't restricted by geography and location, they
would no doubt be interested only in the sperm of the best of the best, thereby
devaluing the stud services of all other stallions. In fact this is the case in
the Standardbred industry. Because artificial insemination is the norm, the
breed has improved much faster in comparison to the Thoroughbred. However, the
Standardbred colt owner must make a profit at the racetrack because unless the
colt is literally the best of the best there is no chance of making a profit on
the colt as a stud (1).
Artificial Insemination
So, if there is no restriction on the decision let's look first at artificial
insemination. The advantages are many starting with the fact that through
artificial insemination the improvement of a particular trait (like our example
of Standardbred trotting/pacing speed) in the breed of horse can be accomplished
comparatively quickly. This is due in part to the ability of a stud to
impregnate many more mares per season than is possible with live cover. With
a wider results base each season, the desired traits are more likely to show and
are more likely to be rebred, therefore producing a quicker time frame of breed
improvement. What then adds to the process is that if these offspring
and only these offspring showing the improvement are selected for stud (as in
the case of Standardbred breeding) the chances of the improved trait
proliferating quickly are even higher.
Other physical and management advantages of AI include the reduced risk of
the spread of both venereal diseases and non-venereal disease such as equine
influenza, strangles and equine infectious anemia (2). One interesting and
helpful break-through is the ability to treat semen to reduce the natural
bacteria content, therefore reducing the risk of uterine infection in prone
mares (2). Along with the ability to impregnate mares with physical
abnormalities (although, if genetic it is generally thought best not to breed
these mares), the risk of injury that can occur with violent mares or stallions
is also completely removed. And of course the last major advantage of AI is that
you don't need to live down the street from the stallion or at least within
practical hauling distance. AI makes it possible
to breed your mare to practically any stud in the same hemisphere without so
much as trying to load your mare into a trailer, not to mention avoiding the mare care fees that often stack up at stud farms,
especially if your mare
doesn't take immediately. The use of artificial insemination can be very
advantageous to the stallion owner as well because he reduces the risk of injury
to his stud and also increases his profits since one ejaculation can breed
multiple mares.
So it sounds ideal, doesn't it? But along with every other scientific
break-though artificial insemination does have its disadvantages. As of
now, results from frozen semen are very poor and therefore the only present
option to prevent the immediate death of sperm is by cooling it. Although, it
does extend the life of the sperm somewhat, there is still a very limited
amount of time in which the sperm must get from stud farm to the interior of
your mare's uterus. The
amount of money spent on same day or next day couriers by mare owners can
sometimes seem very frustrating, especially if it is necessary to have semen
shipped multiple times and can reach upwards of hundreds of dollars depending
on the location of the stud farm. The other disadvantage that is associated with
the use of AI is the increased risk of fraud and/or accidentally breeding the
wrong stud to your mare. It is a lot easier to mistake one tube of semen for
another than it is to mistake one stallion for another. Although the
stallion owner is able to sell more breedings they must be careful not to reduce
the value of the semen (and the value of the Stallions's bloodline) by making it
too easily available. In fact many Standardbred stallion owners have decided to
limit the number of breedings available per season for this very reason. It is also important to
have the semen observed and tested by your veterinarian prior to insemination,
which adds to the issues of time constraint and cost. Overall, however, AI is
considered a highly effective, convenient and safe method of horse breeding.
Live Cover
The advantages of live cover are also important to take into
consideration. For those of you who are not exactly experts at understanding
your mare's reproductive cycle or calculating when she will ovulate, it is a
relief to have these decisions made by breeding experts at the stud
farm. Another possible advantage is the fact that a stallion can cover a mare up
to 10 times in a 24 hour time period, which can increase the chances of
fertilization. Of course this will only be the case if the mare and stallion
have access to each other for this amount of time, for example if they are
turned out together in a pasture to breed without assistance. With controlled
and assisted cover however, chances are that the mare will only be covered
once, reserving further breedings for other mares. The financial advantages of
live cover are illustrated well in the Thoroughbred industry. Because certain
bloodlines are much harder to come by (meaning they are not available through
mail-order) they retain their very high value both in the breeding shed and in
the auction ring. Overall, live cover is
considered a more natural and traditional way of breeding horses.
References & Suggested Reading:
|
