Allegheny Equine Associates

Firstly, you will want to have done some research on, or have a stallion in mind that you plan to breed your mare to. Time is of the essence when breeding your mare effectively, so already having your documents in order (see below) is the first step in providing you with an efficient breeding timeline for your mare.

Secondly, a breeding soundness exam or baseline palpation to determine any defects, health issues, and where your mare is in her cycle is imperative before proceeding with any breeding work. If your mare has any history of issues getting in foal, or has been bred in the past, a uterine culture is also recommended to determine that there are no issues such as infection or inflammation.

Here at Allegheny Equine, there are a few things we will require in order to breed your mare. Firstly, we will require a copy of your completed, signed stallion contract. Any history on the mare and previous foals, fertility issues or complications is also strongly recommended.

We will also need you to set up an account with us (if you have not done so already) as well as an account for your mare(s) that you might be interested in breeding.

It very much depends on the mare and what the stallion you are looking to breed to offers. For example, some stallions offer both cooled and frozen, while others only offer one or the other. There are a number of factors that contribute to successfully breeding your mare.

The biggest difference between frozen and fresh/cooled semen, is that frozen semen has a shorter lifespan and how well the stallion’s semen handles being frozen and thawed. There are some advantages and disadvantages to both.

Frozen Semen: With frozen semen, you have access to a much larger market (virtually worldwide) and that the semen can be kept for a much longer period. However, some disadvantages to frozen semen are the quality of the semen when it is collected and stored, the fertility and health of the mare, and a higher cost versus cooled.

Cooled Semen: Some advantages to using cooled semen is that it can be more viable when it is cooled, and often has a better success rate in older or difficult to breed mares. Cooled semen is also generally cheaper than frozen and could help lower your costs if your mare requires multiple breedings. Some disadvantages when it comes to using cooled semen, are that it needs to be used within 24-48 hours to ensure the best possible motility, or that the semen could possibly not survive or do as well being shipped.

Unfortunately, there are a number of reasons that your mare may not take on the first try, or at all. It is very strongly recommended that you first perform a breeding soundness exam on your mare, especially if she has a known history of difficulty getting in foal. It is recommended that your mare be checked for pregnancy at minimum 14 days post-ovulation. Any earlier is not recommended, since the pregnancy could be missed and even one day does make a significant difference in some cases. There are a few options to consider if you want to try breeding your mare again. Sometimes it’s as simple as the conditions just weren’t right and the mare didn’t take on the first try. It could be that the mare had an irregular ovulation. If it is suspected the issue is with the quality of the stallion’s semen, you could consider changing stallions. If it is suspected the issue lies with your mare, you might consider changing mares.

Ideally, if everything goes smoothly, your mare is brought to the clinic when she begins showing signs of heat. A veterinarian will perform a rectal ultrasound and determine where she is in her cycle (how close she is to being ready to breed).

If she is in heat, or coming into heat, it will be recommended that she be left at the clinic so she can be closely monitored and bred with the time is right. If she does not appear to be close to a heat cycle, you will have the option to leave her at the clinic to continue monitoring, or you may take her home and bring her back for another check when directed by your vet.

Once she has developed a large enough follicle, the veterinarian will order semen for your mare and have it shipped to the clinic, and the mare will be bred (often the following day) as close to ovulation as possible. Sometimes, the mare does not ovulate on schedule, and another dose or another order of semen will be required.

Just like in people, there are a variety of factors that may make it difficult for your mare to become pregnant or maintain a pregnancy, or not be able to become pregnant at all. Such factors could include (but are not limited to): infection, poor genital conformation, the health of the mare (or body condition), age, retained fluid in the uterus (endometritis), or irregular heat cycles.

If you are having difficulty getting your mare in foal, it is best to speak with your veterinarian about what other options are available.

A breeding soundness exam is one of the first steps recommended before attempting to breed your mare. This will help your veterinarian determine if there are any glaring issues (like deformities or infection) that could keep your mare from getting pregnant. Providing history on the mare (whether she is a maiden, if she’s had any history of difficulty getting in foal or carrying a foal to term, etc.) can also help your veterinarian identify any problems that could arise, and make the best possible decisions regarding your mare when it comes time to breed.

Ovulate: The process in which a mature egg is released from the ovary. Most commonly occurs 24-48 hours prior to the end of estrus in mares

Follicle: The fluid-filled sac surrounded by a group of cells that protect and nourish the ovum (egg). While it can vary significantly from mare to mare on what size of follicle they ovulate, most mares do not ovulate on a follicle smaller than 35mm

Anovulatory Follicle: This is an irregular follicle that does not collapse and properly release the oocyte within

Ovarian Cyst: A freely movable structure a short distance from, or within the ovary. Most cysts do not interfere with the mare’s fertility, but larger ones could cause issues with the pregnancy transport to the uterus. Most cysts can be removed via manual reduction.

Heat (or Estrous): Most mares start to come into regular heat in April through August. A typical estrous cycle is approximately 21 days. It is composed of two phases: Estrous (in heat) and Diestrous (out of heat)

Maiden: A mare that has never had a foal before

Ovary: The female reproductive organ in which ova (or eggs) are produced

Uterus: The organ in the lower body of a female mammal where offspring are conceived and in which they gestate before birth

Vulva: The overall term that describes the structures that make up the female external genitalia

Caslicks: A procedure performed by a veterinarian, which involves suturing closed the upper part of the vulva. Most commonly performed on mares with issues to the conformation of their genital area. The caslick MUST be removed 1-2 weeks prior to her due date, or she will tear and cause significant damage

Uterine Lavage: Procedure performed post-insemination to remove dead sperm, debris and other material to prevent inflammation of the uterus.

Pneumabort: A vaccine comprised of a killed virus for use in the prevention of abortion caused by rhinopneumonitis due to EHV-1 infections

Oxytocin: Used to cause uterine contraction and help empty the uterus of fluid

HCG/Chorulon/Histrelin/Deslorelin: Used to achieve optimal conception in mares; drugs used to induce ovulation

Lutalyse: A drug that is used to return a mare to estrus