Once equine semen is frozen it is recommended that a post-thaw analysis be performed in order to ascertain the semen quality. There is variability in how well sperm from different stallions respond to the cellular stress of freezing and thawing. It is important to determine how well the sperm from a particular stallion withstood the stress of cryopreservation in order to make informed decisions regarding the management of their frozen semen inventory and breedings. Also, when we freeze a stallion for the first time we do a test freeze comparing several different protocols. We then use the post-thaw motility to select the freezing protocol for subsequent collections which gives the best post-thaw result. There are industry recommended minimums for commercial distribution of equine frozen semen and therefore it is pertinent to know if your stallion’s frozen semen would qualify. Consequently, the analysis of frozen-thawed semen is a valuable tool for the semen freezing lab, but also for the veterinarian receiving the semen. Your vet may base the breeding management of your mare upon the post-thaw quality of the semen. Also, many vets take a look at the motility of the frozen semen at the time of insemination, for future reference if there are concerns should the mare not check in foal.
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The Test Freeze - The First Freeze Performed on a Stallion's Semen
The test freeze is the first freeze performed on a stallion when he comes to a Select Breeders Services (SBS) Affiliate Lab to have semen frozen. We primarily have four different semen freezing protocols that we test on each stallion. The differences between each protocol being in either the extender formulation or the rate of cooling. For subsequent freezes we choose the protocol which gives the best results as determined by post-thaw motility. Regardless of the protocol, once the straws of semen reach -120 degrees Celsius in the programmable cell freezer they are then plunged into a bath of liquid nitrogen at -196 degrees Celsius.
My Stallion is Not Settling His Mares...What Do I Do? - Part 2
How a stallion owner/manager responds to and handles mare owner concerns regarding semen quality or fertility can make or break a relationship or reputation. This article aims to give stallion owners an overview of the factors involved and provide a systematic guide to troubleshooting a resolution if possible. In Part 1 of this article, published in last month’s newsletter, we discussed the stallion’s breeding history, the importance of a breeding soundness exam (BSE), and stallion management practices as well as semen quality and evaluation. This month in Part 2, we will review common problems identified after the semen evaluation, the relevance of the mare book and their reproductive status and discuss the topic as it relates to those stallions breeding with frozen semen.
My Stallion is Not Settling His Mares...What Do I Do? - Part 1
It is around this time of year that we receive calls for advice from anxious stallion owners concerned about a lower than anticipated conception rate for their stallion, in the hopes of finding some resolution and correcting any potential issues before the end of the breeding season. Time is running out to fulfill those breeding contracts and get those mares pregnant. There are so many variables that contribute to successful conception and pregnancy, from both the mare and the stallion side of things. From the stallion owners perspective they are looking to address the stallion’s semen quality, breeding management and reproductive status. But where to start? This article will give stallion owners an overview and provide a systematic guide to troubleshooting a resolution if possible. How a stallion owner/manager responds to and handles mare owner concerns regarding semen quality or fertility can make or break a relationship or reputation.
Why Freeze Stallion Semen?
All too often we hear tragic stories about the sudden death of a stallion whether it be due to an illness or an accident no one anticipated. He may have been a mature stallion who was already proving himself as a sire or a young stallion but now the world will never know his genetic capabilities. These conversations usually end with the stallion owner saying, “I wish I had frozen semen from him.” Or a mare owner saying, “I wish they had frozen semen on him because he would have been a wonderful cross with my mare.” It doesn’t have to be this way.
Sperm Accumulation in the Stallion
Have you ever wondered what happens to all those sperm the stallion produces every day (5 billion or more)? If he is not bred or collected then where do the sperm go? We know that sperm are produced in the testicle and move from the testicle into the efferent ducts and then into the head of the epididymis. It takes about 7-10 days for sperm to travel from the head of the epididymis to the cauda epididymis (tail; figure middle right). This time frame is not altered by how often the stallion ejaculates. The old wives tale that you can get immature sperm if the stallion is bred too often is just not true. In this article, Dr. Ed Squires and Dr. Pat McCue review the causes, diagnosis and treatment for stallions which accumulate sperm.
Foal Diarrhea - Avoiding it Altogether
A newborn foal’s biggest adversary is infection from pathogens such as Rotavirus, E. coli and Salmonella bacteria. In fact, diarrhea or sepsis (generalized body infection) is the leading cause of neonatal intensive care in foals. The illness starts out as invasion by one of many viruses or bacteria. Rotavirus is highly contagious and happens when foals ingest focally contaminated material or lick surfaces contaminated with manure. One teaspoon of Rotavirus-infected feces from a foal can contain more than 10 million virus particles – enough to infect whole herds of foals. Unfortunately, too, the virus is so hardy that it can survive more than nine months at room temperature and over winter on farms.
Harvesting and Freezing Equine Epididymal Sperm
The sudden death of a stallion is a devastating event, not just emotionally, but potentially financially as well. In addition to any competitive goals the stallion was working towards, his untimely death may mean the loss of future breedings, particularly if a stock of frozen semen was not banked up whilst he was alive. In this situation it may be possible to harvest and freeze epididymal sperm by castrating the stallion immediately after death or euthanasia. Alternatively, collection and freezing of epididymal sperm may be an elective procedure performed at the time of castration. This offers an advantage to young stallions, i.e. some semen can be frozen without taking time out from a busy training schedule, or without exposing a young stallion to the breeding environment. For the mature stallion it represents an additional opportunity to collect semen for freezing. Here we review the process of epididymal sperm harvesting for freezing, and its subsequent application for breeding purposes.
The Pros and Cons of Equine Frozen Semen
The advantages and disadvantages of utilizing equine frozen semen are debated by stallion and mare owners alike. Will I continue to show my stallion or retire him to the breeding shed? Is there an international market for my stallion? What if my stallion is injured in an accident or suddenly dies? Is my mare a suitable candidate for breeding with frozen semen? Is it true conception rates with frozen semen are lower than those when using cooled semen? These are just a few questions to ask when considering whether to utilize equine frozen semen.
What Exactly is a Dose of Frozen Semen?
Is a dose a breeding? Is a straw a dose? How many straws in a dose? How many sperm in a dose? These are often questions we hear from our clients when purchasing or using frozen semen. There is so much variability in the format of doses sold throughout the world that it can be confusing at times. To ensure you have the best opportunity of success when breeding your mare it is important to understand all the elements that determine an adequate dose of frozen semen. Here we review frequently asked questions that relate to what constitutes a dose of frozen semen.