Breeding of mares by shipped semen offers numerous advantages for both the mare and stallion owner. For mare owners, perhaps the greatest advantage is the much increased accessibility of stallions - semen can be shipped thousands of miles, even overseas, therefore giving the breeder a much wider selection of stallions from which to choose. This results in a larger genetic pool, a greater chance of finding the perfect stallion compliment for your mare, and easier access to the top stallions. It can also allow mare owners to add certain desirable bloodlines to their breeding program that might otherwise not be available. As a consequence, the overall quality of foals may increase with choices well beyond those stallions available locally.

Shipping of semen allows the mare to be bred either at home or a local vet clinic, thus eliminating the cost and stress of transporting the mare a great distance to the stallions farm - an added benefit especially if the mare has a foal by her side. Breeding accidents can be serious and are much more prone to occur with live cover, so for the horses involved it is a much safer way to breed. With artificial insemination (A.I.), breeding of those mares that have silent heats (they do not show estrus) or those that will not allow a stallion to mount during estrus can be accomplished. Transmission of venereal infections is lessened by the addition of extenders, which contain antibiotics, to the stallion semen. In addition, some studies show increased conception rates over natural cover, particularly for mares who have had past breeding difficulties.

A.I. also has some added advantages from the standpoint of stallion fertility. Shipping semen requires that the semen is evaluated prior to shipment, so any changes in the fertility of the stallion may be detected sooner than with live cover. One collection of stallion semen may be used to inseminate several (or more) mares, allowing more mares to be booked per season because the semen is used more efficiently. This is a potential benefit to the mare owner if the stallion is heavily bred, as it will be easier to schedule a breeding with shipped semen than with live cover. Also, the extenders added to semen contain factors that support and protect the sperm, which sometimes gives increased pregnancy rates to stallions with low fertility. This benefit is often especially useful for older stallions. The use of frozen semen opens longer-term options, because it may be stored indefinitely and is sometimes used even after the stallion is no longer fertile, or has passed away.

There are a few disadvantages of using shipped semen in your breeding program, the primary drawback being cost. Additional expenses over live cover include the cost of collection and processing equipment to the stallion owner (which may be reflected by increased stud fees to the mare owner). The mare owner will also pay for collection/transport of the semen, and veterinarian fees associated with checking the mare for impending ovulation and insemination of the mare. These fees are quite variable, and in some instances are comparable to or less than those of natural cover, considering the mare care fees of live cover (the mare is boarded at the stallions farm), costs of transporting the mare to the stud farm, and the fact that many stud fees for shipped semen include one or more collections. Another disadvantage is that shipping of semen requires additional experience and education on the part of the stallion manager, and those involved in the collection and processing of the semen for shipment. Also, some stallions might be fertile by live cover but their semen simply does not chill or freeze well, so they can not be used in a shipped semen program.

However, given the many advantages of using shipped semen and few drawbacks, the increase in popularity of breeding by this method is not surprising. Almost all of the breed associations in the U.S. now allow breeding by artificial insemination, with the notable exception of the Jockey Club (Thoroughbreds). However, the mare owner will need to check with the breed registry to ensure that they will register a foal that was conceived by shipped semen, and if so, be sure to adhere to their specific rules regarding storage and transport of semen.

With a bit of education on the part of the mare owner, a good reproduction vet, and a knowledgeable stallion manager, shipped semen can be a cost effective way to greatly enhance the results of your breeding program.

Keys to Success

The key factors for a successful experience when breeding by shipped semen include the fertility of the mare and stallion, the experience/knowledge of the stallion manager and the mares veterinarian, and good communication between the parties involved. It is highly recommended for the mare owner to evaluate these components prior to booking a stallion. The time spent in the beginning on such an evaluation can greatly help to prevent the wasted time, money, and disappointment of an unsuccessful breeding season. This chapter explains how to evaluate these key aspects for success.