Every stallion owner’s worst nightmare: 2 months into the breeding season and your stallion is not settling his mares. His bloodlines are impeccable, and he had a great start to his performance career so this year you offered to stand him at stud to outside mares, and the response has been great, 40 mares booked in his first season! As a responsible and experienced stallion owner, you had a breeding soundness examination done and he passed with flying colors; good testicular size, good sperm production, good motility, concentration and morphology and his semen responded very well in a 48-hour cooled semen trial. He should be able to handle a book of 40 mares without problems.
Obtaining a low sperm count from a stallion can be frustrating and the issue may or may not be able to be remedied depending on the cause. It is best to have a thorough 
Those of us who work with stallions are routinely asked to determine a stallion’s fertility prior to breeding mares or to investigate the cause of low fertility. Often this requires sending the stallion to a specialized veterinary clinic or a veterinary school. Advances have been made in stallion fertility evaluations through the use of computerized sperm motion analyzers (CASA) and flow cytometry.
Diagnosis of infertility in stallions usually starts with a complete reproductive history and then collection of semen to evaluate seminal parameters, testis size and the potential presence of bacteria in the semen. A more detailed evaluation might also include drawing blood for hormonal analysis.
Knowing and keeping track of the concentration, or the number of sperm per milliliter, of each ejaculate for a stallion is very important for a variety of reasons. The concentration of his semen, along with the volume of his ejaculate, is used to determine the total number of sperm he produces in a given collection. These two numbers (volume and concentration) are used to calculate insemination doses. Also, keeping a record of each number can help stallion managers recognize if there are any changes in the reproductive health of the stallion. Slight variations are likely nothing to be concerned about. However, if the number of sperm in the ejaculate varies drastically, from collection to collection or a steady decrease in his total number of sperm over time, one may begin to ask what is causing the change. This information is valuable so that any concerns can be addressed as soon as they arise.
Shuttle or Dual-Hemisphere Stallions are terms used to describe breeding stallions which travel between the Northern and Southern Hemispheres for their respective breeding season. Several questions arise when discussing shuttle stallions and may include: Why do stallion owners incur the costs and risks of sending their stallions thousands of miles away? Does the lack of sexual rest affect their fertility? Is there a way to service mares in a different hemisphere without sending the stallion so many miles away? 
To understand why seminal plasma is beneficial in some situations and potentially harmful in others we must first review what it is, where it comes from and what we think are its roles in reproduction. The term seminal plasma refers to the fluid portion of ejaculated semen in which the spermatozoa are suspended. This fluid consists of secretions from the accessory sex glands in the stallion’s reproductive tract. These include the ampullae, the vesicular glands (seminal vesicles), the prostate gland and the bulbourethral glands (figure 1).
There are many reasons and techniques for collecting a fractionated ejaculate from a stallion. In this article we will discuss some reasons why and demonstrate the technique we have used in our laboratory to manage a stallion with excessive gel fraction that contaminates ejaculates collected using standard in-line filter equipment.
Juvenile and older males entering a new career as a breeding stallion don't have the luxury of a changing cascade of hormones or an event like parturition to jumpstart their innate nature to show them how to be a stallion. There is likely only a change in routine, location, or in their training schedule that cues them into their new roles as breeding animals. Many stallions make the transition seamlessly. Simply acting on the behavior they have been trying to use for years, allowing their behavior to mimic their springtime rise in testosterone. When exposed to a female, they have little doubt about the job at hand and will readily take to live cover or phantom training. Additional information for training the young stallion for collection can be found in our article, 
Dr. Glenn Blodgett is the horse division manager at the 6666 Ranch, a member of the SBS Affiliate Laboratory Network and the current president of the American Quarter Horse Association. In recent years, Dr. Blodgett has implemented the use of chemical ejaculation with one of the stallions in his care. In this article, he will share with us in what situations chemical ejaculation might be useful, recent research performed using the procedure, how he uses it in his breeding program and the success rate of his attempts. 
In our previous article, 
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 
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.
Successfully managing a stallion’s competition and breeding careers requires careful planning. It’s easy to forget that they are essentially being asked to have two distinctly different jobs. Each of his jobs place different physical and mental demands on the stallion and your management approach needs to account for all of those demands.
During those dog days of late summer and the end of the breeding season, most of us who work in equine reproduction are ready for a break. You are left with those difficult mares that didn’t settle earlier in the season and stallions that may be growing tired of breeding. Mares may not cycle as predictably or conceive as readily and stallions may be tougher to collect or exhibit a decrease in semen quality. One of the factors that can contribute to these problems is heat stress. As ambient temperatures rise, stallions and mares may experience disruptions to normal reproductive function as a result. This article will briefly describe some of the effects of heat stress on mare and stallion reproductive function.
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.
Each year, we survey horse professionals all over the world on how they promote their businesses. Word of mouth consistently tops the list but social media is not far behind. The two are very closely related and the reality is social media is word-of-mouth marketing on steroids. Not only are you able to talk to those people right in front of you but with social media you can talk to hundreds or thousands of people at once. 
It is generally known that the quality of semen after freezing is dependent upon how good the semen is immediately after collection and prior to freezing. In some cases there is nothing one can do to improve the quality of the semen collected and one has to deal with the cards he has been given. However, there have been several management factors identified that adversely affect the quality of semen collected. The goal of every collector should be to carefully prepare the AV and collect the stallion on one mount. Each time a stallion mounts and enters the AV and does not ejaculate the pre-sperm is accumulated in the bottle. After each unsuccessful collection attempt the bottle should be replaced with a warm fresh bottle. If this does not occur we know that the quality of the semen will be decreased. 
The advent of transported cooled semen significantly altered the logistics of the equine breeding industry. Shipping semen to mares rather than mares to stallions is incredibly more convenient; however it has resulted in the need for increased proficiency in semen processing techniques on the part of the stallion manager and expertise in reproductive technology and artificial insemination on the part of the field practitioner managing the mare. From the perspective of the stallion manager there are a number of factors that can influence the success of cooled transported semen such as stallion collection management, semen handling, extender composition, dilution rate, cooling rate, calculation of insemination dose and transport device. Our blog article this month will address the basic techniques for proper collection, evaluation and processing of stallion semen for cooled transport.
At SBS, we are often presented with young stallions for semen collection and evaluation. There are a variety of reasons that stallion owners want to have semen collected from their young stallions including; 1) evaluation of sperm production and quality to assess suitability as a breeding stallion, 2) training to collect on a phantom with an artificial vagina in preparation for a breeding career and 3) to collect and preserve semen from a young stallion prior to castration or starting a performance career.
