Fri, 08/05/2022 - 9:36pm

Ice, Ice, Baby

Breeding dogs with frozen semen


Why should I freeze semen on my dog?


If your stud dog has valuable qualities that should be preserved for the future of the breed or your own breeding program, you should freeze his semen when he is young. This will ensure his breeding availability for future generations.

Some medical issues do not develop until later in life — for example, cardiomyopathy or degenerative spinal problems. By preserving his sperm, you can breed back to him years later knowing he was clear of these diseases.

Frozen semen can be used for breedings when the stud dog is not available. There are times when a bitch needs to be bred and the stud dog is unavailable due to show or trial schedule, booked stud services, temporary illness or injury, or any other scheduling conflict. The use of frozen semen ensures the bitch can be bred when she is ready.

Long-distance breedings can be accomplished without having to transport the bitch or the stud dog. International breedings can be done with frozen semen, since there is very little risk of disease transmission and the semen remains viable as long as it is kept frozen until needed.

Freezing semen is also a way to continue using a valuable stud dog after he is neutered. Storing semen ensures good-quality semen will be available at any time.


When is the best time to freeze semen from my dog?


Ideally, semen should be collected from males when they are between 18 months and four years of age. The incidence of prostatic disease increases after the age of five years and has an adverse effect on semen quality. While an older male can still be collected for freezing, a better collection can be expected from a younger dog.

Economically it also makes sense to freeze semen on younger dogs. They usually have a higher number of sperm so you will get more breedings per collection. It is better to collect and store a dog at a young age based on its predicted potential, rather than wait until an older male is in great demand but has less sperm.

Make sure the dog is fit and healthy for the few months before the collection. A sick or stressed dog will not provide a good-quality semen sample. If the dog has had a high fever recently, he may show a significant decrease in the quality of his semen for several months following the illness. Certain drugs may also have an effect on sperm production.

In cases where the male is over six years old, has a history of prostatic disease, or has questionable fertility, it may be advisable to have a semen evaluation and “test-freeze” performed before committing to storage for large amounts of semen that has only a few live swimmers when it is thawed.


How is semen collected?


Semen is collected from the stud dog by manual stimulation. The three different parts, or fractions, of the ejaculation are collected separately. It is the second fraction, known as the sperm-rich fraction, that is frozen and stored.

Semen of better quality with a higher sperm count is collected when the dog’s libido, or sex drive, is high. Try to closely approximate a typical breeding situation for each stud dog. Owners are encouraged to provide a bitch who is in season to use as a “teaser.” Even a bitch of the same breed who is not in season is better than nothing. Very few male dogs perform their best without having the familiar visual cue of a bitch standing in front of them. In addition, if the dog associates a particular item with breeding, such as a rug, table or breeding rack, that item should be brought to the collection.


What other factors affect semen quality and quantity?


In general, large dogs produce more sperm than small dogs. Toy breeds may need several collections to store enough to breed one bitch, whereas a giant-breed dog might produce enough semen in one ejaculate to inseminate three to five bitches. It is the number of sperm cells that is important, not the volume of the collection.

An experienced stud dog usually produces better-quality semen than a dog that has not been bred or collected and doesn’t fully understand what he is supposed to do. Also, a dog that is used to having people around and being handled while breeding a bitch will tend to perform better when having semen collected. You always get better collection results when the dog is relaxed, confident and enthusiastic about the process.


What happens after the semen is collected?


Immediately after collection, the semen is evaluated microscopically to determine if it is of sufficient quality to freeze. At this point, if the semen quality is marginal, a decision can be made to delay freezing to another time and to investigate potential causes for the poor-quality semen.

If the semen is of good quality and meets the minimum required standards to be frozen, the sperm-rich fraction of the ejaculate is diluted in a special fluid called “semen extender” and cooled to 4oC over several hours before being loaded in .5ml straws or formed into pellets. These are then rapidly frozen to -196oC in liquid nitrogen. The number of straws or pellets is determined by the initial sperm count.

Semen extender contains a number of ingredients to protect the sperm through the cooling, freezing and thawing process. The ingredients include egg yolk, antibiotics and cryoprotectants, which protect the sperm during freezing.

After the semen has been frozen, a straw or pellet will be thawed to determine the post-thaw motility. This information is used to determine the amount of frozen semen needed for each breeding. An average post-thaw motility is 40 to 60 percent. This means that 40 to 60 percent of the original sperm cells have survived the freezing and thawing. The owner can decide whether to do additional collections to have more semen frozen depending upon the number of inseminations desired for storage.


How long does the collection and freezing process take?


Typically, the entire process takes three to four hours from the time of the collection. Owners only need to be present for the collection process, which may take 15 to 20 minutes.

How long can the semen remain frozen?

Researchers have estimated that frozen bull semen will last more than 10,000 years. It is presumed that canine semen has similar storage properties. I recently completed successful breedings on bitches of two different breeds with semen that was 28 and 30 years old.


Where is the semen stored?


There are multiple storage facilities worldwide. The semen is stored in 1,500-gallon liquid-nitrogen tanks. The semen is held in liquid nitrogen vapors at a temperature of -196oC, or approximately 300 degrees below zero Fahrenheit. The nitrogen level in the tanks is monitored constantly. Since the container does not require electricity, there is no fear of accidental thawing due to a power failure. Many facilities have security measures including restricted access and security guards patrolling the property.


What is the success rate for breeding with frozen semen?


Individual success may vary depending on the semen quality, bitch fertility, accuracy of the ovulation timing and procedures used for insemination. Most veterinary reproductive specialists recommend surgical or trans-cervical insemination when using frozen semen. When thawed, the semen is only viable for 12 to 24 hours, so accurate ovulation timing and placement directly into the uterus help ensure fertilization. It is best to investigate your options before the bitch comes in season.




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