Today's breeding technology provides horse owners more options than were available in the past. Artificial insemination and semen preservation techniques make it possible to ship stallion semen to mares nearly anywhere in the country. But success with transported semen will depend on the careful reproductive management of both stallion and mare. more...

Artificial insemination (AI) is becoming an increasingly popular method for breeding horses, and with that comes advances in the timing methods used to inseminate mares. "Breeders have embraced the use of transported cooled semen for all the benefits associated with shipping semen to mares as opposed to shipping valuable mares and foals to stallions for live cover or on-farm AI," said Paul R. Loomis, MS, CEO of Select Breeders Services in Colora, Md., at the Hagyard Bluegrass Equine Symposium held Oct. 21-23, 2004. more...

Veterinarian’s input in evaluating a broodmare increases the odds of a successful purchase. The goal when purchasing a broodmare at public auction is to select an individual that will produce one foal per year during the mare’s reproductive career. Involving a veterinarian in the selection of additions to your broodmare band can be beneficial in assessing the degree of risk involved in buying at public auction. more...

Artificial insemination (AI) using chilled semen involves the collection, evaluation and dilution of semen from the stallion and then, the TIMELY infusion of an adequate number of sperm into the mare's uterus. The semen must be processed adequately to insure that it retains its fertilizing potential. A successful AI programme depends upon: more...

We often think of pregnancy as a delicate and fragile condition. When it comes to horses, this perception is perhaps due to the mare's relatively poor reproductive performance in comparison to other domestic animals. However, in a natural setting, the mare does comparatively well reproductively. Therefore, this seemingly poor performance is due as much to improper management as to any reproductive deficiency. Fortunately, management is something we can control. more...

The mare's natural breeding season is during the summer but many breeders try to get their mares in-foal in mid-February to ensure foals are born as close to 1 January as possible more...

I often hear breeding-related "theories" that make me chuckle. Included here are some with explanations, and I will be adding to them periodically as I hear more, I am sure! more...

When you drive by a farm and see a bright, playful young foal romping in a lush pasture with his dam, it's easy to forget how much work, money, and planning went into his breeding. Many people underestimate the planning that goes into a useful, profitable mating.
The first step in the process is getting the opinion of a qualified veterinarian as to whether your mare can and should be bred. You should also determine the approximate value and usefulness of the resulting foal, and the cost involved. Many horse owners fail to consider costs other than the stud fee, more...

Breeding or inseminating a mare induces an immediate inflammatory response in the uterus. This is a physiological reaction against foreign material. In most mares this inflammation clears within 1 or 2 days. Mares susceptible to mating-induced endometritis are known to accumulate fluid in the uterus as a result of impaired clearance of inflammatory products. Reduced myometrial contractions, poor lymphatic drainage, a large, overstretched uterus and cervical incompetence are predisposing factors for persistent-mating induced endometrititis.
It is particularly important to recognise and manage appropriately the older maiden mare more...

By the time a broodmare enters her late teens and early 20s, her reproductive ability begins to decline, and getting and keeping her pregnant become more problematic. The causes of reproductive difficulties in the older mare are numerous, but in many situations, good management, accurate diagnostics, and appropriate medical or surgical therapies can optimize the chances of producing healthy foals right up until the time there are essentially no more eggs in the basket. more...

The body condition of a broodmare can affect reproductive performance and milking ability. Recent research has indicated that mares should be kept in a minimum body condition score of 5.5. This body condition is referred to as moderately fleshy, and mares in this condition can be expected to cycle earlier in the year more...

Now is the time for the most important decision of the year for Thoroughbred breeders — choosing the right stallion for their mares. The choice of a stallion is the single most important decision a breeder will make in a year. Yet sometimes it can be difficult to believe that there has more...

It is widely acknowledged that the nutritional requirements of sports horses – show jumpers, dressage horses and eventers – cannot be met by high-bulk, low-energy forage, such as hay, alone. As a result many owners successfully feed their performance horses a diet that includes energy-dense feedstuffs such as cereal grains, which they know will meet the horse's needs. more...

Prior to a colt foal being born his testicles are "stored" within the abdominal cavity. Shortly before birth they descend through the inguinal ring, and into the scrotum. Sometimes for a variety of reasons one or both (more commonly one) do not descend as they should. The vaginal rings close during the first two weeks of the foal's life, and this will prevent a testicle that has not fully descended from the abdomen at that point from subsequent descent. more...

Well, the simple answer is that if you don't know, she probably doesn't need it! Regumate1 contains the drug Altrenogest, a synthetic progestagen, and is labeled for use in mares to suppress estrus (heat) display. In recent years, some have presented it as having an almost legendary ability to support pregnancies in mares that otherwise appear unable to retain the pregnancy through to birth. Is this truly an ability, or just a legend? more...

You've read all the articles at Equine-Reproduction.com, your mare was in heat, you jumped through all the various hoops you needed to in order to get your mare bred, and now you're excitedly awaiting your veterinarian's verdict as to whether or not she is pregnant. The ultrasound screen shows a strange selection of white, grey and black blobs, and you anxiously await the veterinarian's explanation of what you are looking at...
But when the word comes, it's not what you wanted to hear... TWINS!!! Oh no! Now what? more...

This article will attempt to cover a very broad and involved subject area in a way helpful to the veterinarian in practice. Some of the more relevant questions are:
What is the optimum time to diagnose pregnancy in the mare?
Why is this not always possible in practice?
What are the ultrasonographic signs of early embryonic death in the mare? more...

No one ever said mothering was easy. As your broodmare gets closer and closer to her due date, you've been noting, with some satisfaction, her bulging belly, her increasingly matronly attitude, and the look of lazy contentment in her eyes. But while she might look relaxed on the outside, inside, her growing foal is making ever-increasing demands on her body. Those demands won't stop when she gives birth, either. As any mother will tell you, that's when the real work begins! more...

Advanced reproductive technologies that can be used in horses are expanding every year. Geography is no longer a limiting factor in choosing a mate for your mare, as fresh cooled semen can be shipped across North America with ease. Frozen semen also means stallions from other continents can be used. Frozen semen allows for the continued breeding of a stallion even after he dies (for those breeds that allow it). Embryo transfer--once uncommon and expensive--is now commonplace more...

Embryo transfer has sound practical applications: for mares that get in foal readily and yet are unable to carry their own foals to full term; for mares that have foaling problems; and, possibly the most important, so that mares that are successfully competing can breed a foal without interrupting their careers. Normally a top class mare would have to wait until

It is little more than a decade since breeders in the British Isles began to realise that artificial insemination (AI) might have a useful role to play in horse breeding. Before, that, most breed societies would not register foals conceived by AI and there were a number of widely held misapprehensions about the technique. Many people were convinced more...

A stallion needs to be in optimum health and physical fitness to cope with the rigours of regular covering and to help ensure maximum fertility. The nutritional requirements of a busy covering stallion are the equivalent of a performance horse and become even greater if the stallion is competing, as well as undertaking stud duties.
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As the breeding season winds down and spring becomes summer, the primary focus on breeding farms is preparation of yearlings for the sales. The stakes are clearly high as vast sums of money are on the line--rightly or wrongly, the overall "presentation" of a yearling at the sales has a strong bearing on price, regardless of breeding. Plain and simple, poorly "fitted" yearlings won't cut the mustard. more...

A healthy foal will grow rapidly, gaining in height, weight and strength almost before your very eyes. From birth to age two, a young horse will achieve 90 percent or more of its full adult size, sometimes putting on as many as 3 pounds per day. Genetics and environment play significant roles in determining individual growth patterns. Through research, we also know we can influence a foal's growth and development-for better or worse-by the nutrition we supply. more...

Your prized mare has just given birth to her first, long-awaited foal. The whole family and several of your friends have stayed awake to watch the event. The new filly foal appears healthy and strong as she quickly begins her attempts to stand. The foal, after several spectacular crashes, finally makes it to her feet. As flashbulbs go off, your mare suddenly becomes anxious, then obviously distressed. She lunges at the foal, ears pinned, teeth bared more...

Estimated breeding values can be used to rank potential breeding animals for one or more traits of interest. Over the past few decades, several genetic evaluation systems have been implemented in sport horse breeding. Although breeding values can be used to increase performance ability by genetic selection, breeding values are not always well accepted by practical breeders. The use of breeding values becomes even more complicated if breeders want to interpret foreign breeding values. PDF file 2 pages, 77KB more...

Loud-colored horses command high prices. Of course they must be acceptable in conformation. Horsemen often ask, "How can I get a certain coat color?" or "Why did I get so much difference in the foal's color compared to its parents' color?" Some colors are easy to get because only one pair of genes is involved. Generally speaking, the louder the coat color, the more complex the inheritance and the more difficult it is to produce. more...

Jonathan Pycock explains how to maximise the chances of breeding successfully from your mare early in the spring
Breeders should plan well ahead of the breeding season to put a mare in-foal. This allows a suitable stallion to be selected and the mare to be prepared. more...

As there are a variety of methods to start a breeding stallion, both for collection and live cover, for the sake of this article, we'll assume that nothing has been done with the stallion, i.e., he has not been bred live cover or artificially collected. more...

You look at that little 14-hand cutting mare which you have decided to breed. She's a dandy, you think, but just a little small for general ranch work or pleasure riding. So, you take her to that 16-plus-hand Thoroughbred in the next county and breed her. Eleven months later, you walk out to the barn and there in the stall is a newborn foal which has just struggled to its feet and is nursing for the first time. more...

As the time approaches for many of this year's foals to be weaned, Horse & Hound looks at how the right preparation and diet can lessen any negative impact more...

How much advantage for a particular trait do superior animals transmit to their offspring? Heritability estimates help us answer this important question. This publication explains the meaning of heritability estimates, how they are calculated and their influence in changing livestock performance. more...

This will focus on a personal approach to the practical problem of management of the highly susceptible mare which the author has found to work well in daily veterinary practice The objective of the veterinarian and breeding farm owner/ manager should be to produce the maximum number of live, healthy foals from mares bred during the previous season. We could add 'as early as possible' to this in many breeding programs. One of the main obstacles to this goal is the mare which is susceptible to recurrent acute endometritis following breeding.
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Various mating schemes of animals are classified under two broad categories inbreeding and outbreeding. Classification depends on the closeness of the biological relationship between mates. Within each category, a wide variation in intensity of this relationship exists. A very fine line separates the two categories. Mating closely related animals (for example, parent and offspring, full brother and sister or half brother and sister) is inbreeding. With less closely related animals (first cousins, second cousins), people disagree about where to draw the line between inbreeding and outbreeding. PDF file, 10 pages, 30KB more...

Mares have the capacity to be notoriously unpredictable in the timing of their ovulation. This can lead to frustration, aggravation and distress in the owners and attending veterinarians! What signs may one hope to see that could provide some mile markers along the way? Let's lay out some ground rules, but remember that mares make a point of not following rules, so there will always be exceptions! Note that we are referring to full-sized horses and ponies in this outline, not miniature horses. more...

Researchers from Utrecht University in the Netherlands have documented a method to evaluate the jumping ability of horses as young as six months of age to see if their athleticism continues with them as they grow older. While breeding plays an important role in the athletic abilities of a horse, determining the jumping ability of a foal before large amounts of time and money are invested more...

There can be several reasons for a large ovary in a mare. The three most important are:
(1) A normal ovary during the transition or breeding season with large follicles as frequently detected during early spring, persistent luteal phase and early pregnancy;
(2) A solid neoplastic lesion, such as a granulosa theca cell tumor, teratoma, dysgerminoma, cystadenoma and carcinoma;
(3) Hemorrhagic and luteinised follicles more...

Horse & Hound reports from the Thoroughbred Racing and Breeding seminar, where some of the latest research into links between conformation and performance was revealed. A horse's conformation is determined by the arrangement of underlying muscles, bones and other tissues. Many vets are certain that a relationship exists between faulty conformation and the development of lameness, but firm facts are hard to come by. more...

From prehistoric to modern times, the horse has played a vital role as a beast of burden in many fields as diverse as agriculture and warfare. In many developing countries, the horse is still the major form of transport for people and their possessions, whereas in the western world it has become an animal of sport and pleasure. In particular, flat racing has raised the value of individual Thoroughbreds to the level where an unproven yearling has commanded a price tag of $13.1 million (Seattle Dancer, sold in 1985 at auction in Kentucky). Clearly the pedigree of such a horse is a major factor in establishing such high esteem, and an increased understanding of the inherited factors that underpin valued traits will therefore be of interest to the horse-breeding industry. The generation of a genetic linkage map of the horse is the first step toward dissecting inherited factors that affect conformation, soundness, and ability, in a scientific and methodical manner. PDF file, 12 pages, 514KB more...

WHAT has the Equine Genome Project revealed about the ‘tail-male’ line in pedigrees – that is, a horse’s pedigree traced exclusively through its parental line of descent? Just that the Y chromosome, the one determining maleness, is the only thing passed uniquely through sires. more...

Eliminating dust in a horse’s environment can lessen winter respiratory problems. One of the most common winter problems in horses is chronic obstructive pulmonary disease (COPD). Veterinarians now call the condition recurrent airway obstruction, but it is also known as heaves, recurrent airway disease, inflammatory airway disease, small airway disease, chronic bronchitis or bronchiolitis, equine asthma, emphysema, broken wind, chronic airway disease, and hay sickness. When a horse is confined in a barn, more...

Several different types of Equine Herpesvirus (EHV) exist. Whereas one type (EHV-4) only causes
respiratory disease, another, E H V-1, also causes abortion and paralysis. Of these syndromes, paralysis is the most unusual manifestation of infection within this virus. However, when paralysis does occur, it is not uncommon for the infection to cause several cases of disease on the same premises; very careful diagnosis and control measures are thus indicated if a case is suspected. This article first appeared in the January 1997 issue of Breeding News for Sport Horses To subscribe to the magazine please visit their web site www.breedingnews.com/ PDF file, 1 page, 47KB more...

Phantom training is not as hard as one might imagine it to be. It involves conditioned reflex response (remember "Pavlov's dogs" from school science?) The response is of course ejaculation. The condition the stallion must undergo to achieve that is to mount the phantom mare (also known as a breeding dummy) and breed the AV. more...

This presentation will neither be a review of ALL possible approaches to the management of the susceptible mare NOR a review of treatments for endometritis such as
systemic antibiotics
intrauterine plasma
antiseptic intrauterine agents
minimum contamination techniques
A more extensive account of the aetiology, pathogenesis and treatment of endometritis in the mare can be found at the end of this lecture more...

The 19-year-old multiparous pregnant Percheron mare illustrated seen at left is presented to you with a rapidly enlarging abdomen. The owner is concerned about the abrupt development of an extensive area of painful oedema on the ventral abdominal wall. She is 325 days from the last covering date and has exhibited increasing depression and discomfort during the previous 24 hours. Rectal examination more...

Initially some understanding of normal expectations of fertility are useful:
For Thoroughbred mares in the UK the pregnancy rate has increased from a low of 61.2% in 1971 to a high of 72.4% in 1989 (date of pregnancy determination not specified). Similarly, the live foal rate has increased from a low of 53% in 1971 to a high of 66% in 1989 (Ricketts and Young, 1990). For the Hunter Improvement Scheme the current live foal rate is around 60%. Ponies tend to have better rates.
Pregnancy rates at the end of the season will depend on: (1) the fertility of the stallion; (2) the fertility of mares; (3) and the management of the pregnant mare.
This last factor is often related to the value of the horses involved, i.e. frequent veterinary attention
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It's nearing the best time of the year again--foaling season. Although most foals are born in the spring of the year, between February and June, sometimes we see foals in late December or early January. Often these tiny newborns delivered to our hospital around Christmas are preemies (premature foals), but of course, premature foals can be delivered at any time during the season. In the past, a premature foal was regarded as a lost cause with little chance of survival and less hope of being an athletic adult more...

If your mare has made it through 11 months of pregnancy, you're almost home free. Labor and delivery, while momentous, are generally uneventful. In most cases, you will simply need to be a quiet observer--if, that is, you are lucky enough to witness the birth. Mares seem to prefer to foal at night in privacy, and apparently have some control over their delivery. Despite your frequent visits to the barn, your mare may give birth the minute you step away. While this is disappointing, don't worry. She is unlikely to need your help anyway. However, in case problems arise, it is advisable to have your veterinarian's telephone number nearby. more...

Horse breeding is a time-consuming and expensive business. To optimise their chances, owners need to know before the breeding season how best to ensure their mares are free from any diseases that could not only reduce the likelihood of conception, but also severely disrupt breeding activity at the stud. more...

Once you have decided to put your mare in foal, it's important she is correctly prepared to help maximise her chances of conceiving and help avoid costly, repeat visits to the stallion or lengthy spells at stud.
Mares who are significantly over or under weight are less likely to conceive so if your mare needs to lose or gain a lot of condition, the sooner you make the necessary adjustments to her diet the better.
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Breeders cannot change Mendelian genetics, nor the number of genes involved in traits, nor their linkage relationships. They cannot change the physiological interactions of gene products, but they can hope through selective mating to realize gene combinations that consistently result in high quality stock. more...

Fall is the perfect time to check broodmares for breeding soundness for the coming year. A broodmare should be examined by a veterinarian before she is bred--preferably in the fall if she is barren and soon after she foals if she is to be bred again--to make sure her reproductive tract is healthy and capable of carrying a foal to term. Issues to consider are her age, general health and body condition, the condition of her teeth, and her reproductive history. A lameness or chronic problem that causes discomfort should be evaluated. more...

Ultrasound-guided transvaginal oocyte aspiration provides an excellent non-invasive method for obtaining equine oocytes. The recovered oocytes can then be used in in-vitro fertilisation or other programmes or used for other purposes. This method of oocyte recovery is still relatively recent and there is a lack of detailed information available for those wishing to attempt the technique in the horse. The purpose of this paper is to provide a review of current techniques and equipment used and provide information more...

The center of the Colorado State University (CSU) veterinary school's equine reproductive universe is its 22,000-square-foot Animal Reproduction and Biotechnology Laboratory and a smaller satellite, the Equine Reproduction Laboratory. In these facilities, faculty members, graduate students, post-doctorate fellows, and visiting scientists from around the world work more...

The average time needed for placental expulsion is about one hour and should not take more than two hours. However, there is debate amongst equine clinicians with respect to the time interval in this definition and recognition of the precise time at which the process has become pathological is difficult. Most clinicians consider more...

The latest techniques mean ultrasound can be used to confirm the sex of a developing foal as it grows inside its mother. Since its introduction in the early 1980s, the use of ultrasound scanning has increased considerably and had an enormous impact on horse breeding. Ultrasound was originally used only for pregnancy diagnosis but it is now an integral part of the management of mares at all stages of their reproductive cycle. more...

Nature has done a commendable job in developing the equine reproductive system, but it did not take into consideration man's special needs for the production of horses at certain times or under specific circumstances. The first man-made rule for some breeds involved birth dates. People decided for some registries that every equine was a year older on Jan. 1 following its birth year. This means it is important for foalings to occur early in the year to allow the youngster more...

The mare has a relatively long gestational period and, therefore, for the mare to be a yearly producer she must be back in foal, on average, 25 days from parturition. Consequently it is important to understand all the processes that take place in the period from parturition to the restoration of a state supporting the initiation and maintenance of another pregnancy (this period is often termed the puerperium). more...

Artificial insemination (AI) with frozen semen involves the TIMELY infusion of an adequate number of sperm into the mare's uterus. To ensure success in an AI programme knowledge of the reproductive physiology of the mare is very important. Mare selection as well as close monitoring of the cycle are key factors that will determine the success of a breeding programme. A successful AI programme depends upon: more...

Successful breeding of horses is not always as easy as presenting a receptive mare to a fertile stallion. There are many things that can go awry with the reproductive process. Broodmares that were once fertile and produced many excellent foals might one day face the realities of repetitive foaling injuries, chronic uterine infections, or simply old age. Stallions also can experience a decrease in sperm number and quality as the years pass. more...

One of your main objectives whether owning or working with brood mares should be to produce the maximum number of live, healthy foals from the mares bred during the previous season. Perhaps the biggest obstacle to achieving this aim is the problem-breeding mare. The biggest category of problem breeding mare is the so-called "dirty mare". more...

Sometimes it can be quite difficult to get a mare pregnant, especially if she has fertility problems. There are several reasons that a mare might be infertile, many of which can be treated. Two reproductive specialists from Lexington, Ky., shared their extensive knowledge of several of the problems that mares can face with attendees of the Thoroughbred International Exposition and Conference in Lexington, Ky., June 20-22. more...

The use of frozen semen has long been promoted as complicated and time consuming. Veterinarians and reproductive specialists have often been unenthusiastic about its use because of the intensive monitoring believed to be necessary in order for it to be successful. It is acknowledged that the best pregnancy rates are achieved when the semen is inseminated no more than 12 hours before or 6 hours after ovulation. more...

Even though we think a stallion should know his business in the breeding shed, that is not always the case at the beginning. "Starting a novice breeding stallion can range from a quick and easy project accomplished in a few brief sessions to a challenging and time-consuming effort over many sessions and even a few weeks," says Sue McDonnell, PhD, a Certified Applied Animal Behaviorist and head of the Equine Behavior Lab of the Veterinary School of the University of Pennsylvania more...

The horse was the species in which the use of veterinary ultrasongraphy was initially developed. Real time B-mode grey scale ultrasound scanning was first used in equine reproduction for pregnancy diagnosis in 1980.
Ultrasonography provides the opportunity to
Diagnose pregnancy earlier and more accurately than by using rectal palpation
Allow for effective twin management
Detection of early embryonic death. more...

The introduction of transrectal ultrasound technology to visualise the reproductive tract in mares (Palmer and Driancourt 1980) has allowed cyclical changes in the ultrasonic morphology of the reproductive tract to be studied. One of the most striking characteristics as visualised using ultrasonography is the appearance of the endometrium during the oestrus cycle. During dioestrus, individual endometrial folds are not visible more...

New artificial insemination techniques are being developed to enable mares to become pregnant using less sperm,
For those of us involved in the equine breeding industry, it is obvious that artificial insemination (AI) is set to play an ever-increasing role in the future. One of these areas of growth will be in the technique of deep uterine insemination (DUI) when using frozen semen. more...

Three veterinarians share their experiences on one day at the Keeneland September yearling sale.
SEVERAL HUNDRED yards from the Keeneland sales pavilion, where the rhythmic chant of the auctioneers serves as the official soundtrack for the record-setting September yearling sale, Michael Chovanes, V.M.D., is engrossed in the same chaotic tune he has been listening to for years. As the longtime veterinarian from Alburtis, Pennsylvania, methodically rattles through countless more...

Vulval Conformation, Common Vulval Injuries and the Caslick's Procedure
In the normal mare the vulva provides the first effective barrier to protect the uterus from ascending infection. The "normal" mare has three functional genital seals forming a barrier between the external environment and the uterine lumen: more...

Most responsible stallion owners require a "clean uterine culture" from a mare prior to breeding her live cover or possibly shipping semen to her, and this has been the case for many years. It is well known however, that the results of an endometrial swab culture alone are, at best, not a reliable indicator of uterine pathogenicity, and at worst a false positive may result in disastrous consequences. more...

Prostaglandin F2á is commonly used in the mare to cause her to enter estrus (come in to "heat"). It does this by destroying a structure that forms on the ovary following ovulation called the Corpus Luteum ("CL")1. The CL secretes the hormone progesterone, which prevents the mare from displaying receptivity to a stallion. more...